Effect of DNA Base Modification on Polymerase Chain Reaction Efficiency and Fidelity

Polymerase stop assays, used to quantify DNA damage, assume single lesions are sufficient to block thermostable DNA polymerase progression. To explore this assumption, 90 base oligonucleotides containing normal or modified DNA bases were amplified using real-time PCR. Data implied that the PCR efficiency was influenced to differing degrees depending on which base lesion was present on the input oligonucleotide; specifically, while reactions with templates containing a single 8-oxo-7,8-dihydro-2í-deoxyguanosine (8-oxodG) were not noticeably altered, the presence of a single 8-oxo-7,8-dihydro-2í-deoxyadenosine, an abasic site, or a cis-syn thymidine dimer (TT dimer) dramatically delayed amplification. In addition, the presence of two tandem 8-oxodGs substantially hindered amplification when compared with two 8-oxodGs separated by 13 bases which indicated that the position of lesions also influenced the PCR. To quantify variations in amplification, novel mathematical formulae were developed which report differences in exponential amplification as rates of damage bypass. These treatments assume each template in the PCR is damaged to the same degree. Quantification of damage to cellular DNA, which is a mixture of damaged and undamaged template, required further refinement of real-time PCR mathematics; differences in amplification were defined in terms of damage probability (lesion frequency) rather than lesion bypass rate. The validity of these formulae was determined using DNA samples quantified previously using current polymerase stop methods. In addition to impacting reaction efficiency, DNA base modifications decreased reaction fidelity. In reactions with templates containing 8-oxodGs, both the normal Watson/Crick association with dCMP as well as the incorporation of dAMP occurred at the lesion site. Despite similar structural characteristics, the existence of 8-oxodA resulted in a pronounced n-1 deletion in addition to the normal association with dTMP. Sequence data from abasic and TT dimer modifications were inconclusive but suggested the presence of multiple nucleotide incorporation events opposite the modifications. The present work enabled the adaptation of real-time PCR for DNA damage quantification, identified DNA base lesions as potential PCR mutagens, and provides the basis for further refinement of polymerase stop assays as research and clinical tools to monitor DNA damage and repair

Ethical leadership: What is it and why does it matter?

The research aims at exploring the influence of ethical leadership on employees’ behaviors on an individual level. It first studies the research that has been done on ethical leadership in order to provide an overview, and then explores the potential outcomes triggered by the phenomenon on employees’ behaviors. A quantitative analysis was employed with a survey of 131 respondents realized via emailing and social media. The study suggests that ethical leadership influences different variables both positively and negatively. One the one hand, it influence positively related with moral awareness, job satisfaction, motivation, and prosocial behaviors. On the other hand, ethical leadership is negatively related with organizational misbehaviors and counterproductive work behaviors.A pesquisa visa explorar a influência da liderança ética no comportamento dos funcionários em um nível individual. Primeiramente, ele estuda a pesquisa realizada sobre liderança ética para fornecer uma visão geral e explora os possíveis resultados desencadeados pelo fenômeno no comportamento dos funcionários. Uma análise quantitativa foi empregada com uma pesquisa de 131 respondentes realizada via e-mail e mídia social. O estudo sugere que a liderança ética influencia diferentes variáveis, tanto positiva quanto negativamente. Por um lado, a influência está positivamente relacionada com a consciência moral, a satisfação no trabalho, a motivação e os comportamentos prósociais. Por outro lado, a liderança ética está relacionada negativamente com os maus comportamentos organizacionais e com os comportamentos de trabalho contraproducentes

Achievement Orientation: Projective and Objective Measures of the Veroff Model and Their Relationships to Job Reward Values Orientation

The area of achievement motivation research has been fought with theoretical and methodological controversy. The unitary construct of achievement motivation has been challenged by alternative models suggesting several dimensions of achievement orientation. Assessment methods have also been controversial with some researchers preferring objective measures while others prefer projective measures. A third problem in this research area involves the choice of appropriate behavioral or performance correlates of motivation in order to provide a measure of construct validity. The purpose of the present study was to further explore one model of achievement orientation, the Veroff (1977) model which posits six distinct orientations toward achievement. They are Autonomy, Power, Social Approval, Competition, Task Mastery, and Effectance. The relationships between the projective measure of achievement orientation (Depner & Veroff 1979), an objective measure developed for this study corresponding to the projective measure, and subjects\u27 self-reported orientation toward their future jobs was explored. It was hypothesized that Autonomy achievement is associated with the value of intrinsic job factors, Social Approval is associated with the value of work environment, and Power achievement is associated with the value of long term job rewards. Results of canonical correlation analysis indicate that overall the projective measure of achievement orientation was not significantly related to the job reward values orientation measure. The predictions of specific relationships among the achievement and job reward orientations were not supported. However, the canonical correlation analysis did reveal a significant overall relationship between the objective measure of achievement orientation and job reward values orientation and two of the three predictions of specific relationships between the measures were supported by the data. Possible explanations of the failure of the results utilizing the projective measure to support the predictions are discussed and the implications of these results for future research are explored

The use of drones for recreational impact monitoring of public lands

Master of ScienceDepartment of Horticulture and Natural ResourcesRyan L. SharpA significant increase in visitation to protected lands, such as wilderness areas, parks, and wildlife refuges, has been observed across the board, from the smallest of state parks to some of the largest national parks in the world. This rise in use has prompted concerns that visitation is degrading the plants, soils, water, and wildlife these areas were established to protect. The Interagency Visitor Use Management Framework (IVUMF) provides guidance to professionalize the process for the continued preservation of natural conditions and processes in protected natural areas and the sustained administration of high-quality recreational experiences. At the core of the IVUMF is the need to measure indicators and thresholds to both provide sound rationale on which to base new management decisions as well as measure the efficacy of enacted decisions over a long period of time. As public land managers seek to increase the implementation of simple and cost-effective methods to collect indicator and threshold data to address environmental and visitor experience concerns, drones may be the logical next step. This study analyzes the outcome of using a drone to formulate thresholds for two selected indicators, visitor-created trails and vegetation loss, in a newly established Kansas state park, Little Jerusalem Badlands. Up to a 42% loss in vegetation is already being observed in key areas of Little Jerusalem, as well as the formation of visitor created trails after the first three months of park opening consistent with the previously studied curvilinear rate of impact to a site. These results confirm the need for a simplified and reliable method to monitor a variety of environmental indicators in protected areas over the long-term to aid land management agencies in decision-making to reduce recreational impacts

Climate, Ecological Security and the Ukraine Crisis: Four Issues to Consider

In an analysis released early this year, the Center for Climate and Security (CCS) noted that climate change and climate security risks are not separate from other security challenges facing the United States—instead, they are overlapping and interconnected. The Russian invasion of Ukraine is no exception. Climate change is shaping the national security landscape against which this crisis is unfolding, from the tactical to the strategic level. The Ukraine crisis exemplifies the importance of integrating a climate security lens into foreign policy—while climate stress is not the catalyst for conflict in this case, without an understanding of climate and energy transition dynamics brought to the table, policymakers may get key analytic questions and their answers wrong while also missing opportunities for constructive policy interventions.In this briefer, we discuss four key areas of climate and ecological security that are linked to the crisis in Ukraine: 1) The need to accelerate the clean energy transition; 2) Degradation of Ukrainian ecological security; 3) Decreasing global food security; 4) Russia's own climate security vulnerabilities