Saint Mary's University

About: Saint Mary's University is a education organization based out in Halifax, Nova Scotia, Canada. It is known for research contribution in the topics: Population & Stars. The organization has 1931 authors who have published 4993 publications receiving 143226 citations.

Transcription factors and their genes in higher plants functional domains, evolution and regulation.

Abstract: A typical plant transcription factor contains, with few exceptions, a DNA-binding region, an oligomerization site, a transcription-regulation domain, and a nuclear localization signal Most transcription factors exhibit only one type of DNA-binding and oligomerization domain, occasionally in multiple copies, but some contain two distinct types DNA-binding regions are normally adjacent to or overlap with oligomerization sites, and their combined tertiary structure determines critical aspects of transcription factor activity Pairs of nuclear localization signals exist in several transcription factors, and basic amino acid residues play essential roles in their function, a property also true for DNA-binding domains Multigene families encode transcription factors, with members either dispersed in the genome or clustered on the same chromosome Distribution and sequence analyses suggest that transcription factor families evolved via gene duplication, exon capture, translocation, and mutation The expression of transcription factor genes in plants is regulated at transcriptional and post-transcriptional levels, while the activity of their protein products is modulated post-translationally The purpose of this review is to describe the domain structure of plant transcription factors, and to relate this information to processes that control the synthesis and action of these proteins

The discovery of the first “changing look” quasar: new insights into the physics and phenomenology of active galactic nuclei

Abstract: SDSS J015957.64+003310.5 is an X-ray selected, z = 0.31 active galactic nucleus (AGN) from the Stripe 82X survey that transitioned from a Type 1 quasar to a Type 1.9 AGN between 2000 and 2010. This is the most distant AGN, and first quasar, yet observed to have undergone such a dramatic change. We re-observed the source with the double spectrograph on the Palomar 5 m telescope in 2014 July and found that the spectrum is unchanged since 2010. From fitting the optical spectra, we find that the AGN flux dropped by a factor of 6 between 2000 and 2010 while the broad Hα emission faded and broadened. Serendipitous X-ray observations caught the source in both the bright and dim state, showing a similar 2–10 keV flux diminution as the optical while lacking signatures of obscuration. The optical and X-ray changes coincide with g-band magnitude variations over multiple epochs of Stripe 82 observations. We demonstrate that variable absorption, as might be expected from the simplest AGN unification paradigm, does not explain the observed photometric or spectral properties. We interpret the changing state of J0159+0033 to be caused by dimming of the AGN continuum, reducing the supply of ionizing photons available to excite gas in the immediate vicinity around the black hole. J0159+0033 provides insight into the intermittency of black hole growth in quasars, as well as an unprecedented opportunity to study quasar physics (in the bright state) and the host galaxy (in the dim state), which has been impossible to do in a single sources until now.

Use of ab Initio Calculations toward the Rational Design of Room Temperature Ionic Liquids

Abstract: Ionic liquids are gaining substantial interest as alternative reaction media. Despite the overwhelming amount of evidence suggesting a relationship between their structure and melting point, there still remains the problem of selectively choosing a particular ionic pair that will produce a liquid at room temperature. Ionic liquids based on 1-alkyl-3-methylimidazolium halides have been investigated using ab initio calculations utilizing Gaussian 98 and the 6-31G* and 6-31+G* basis sets. The calculated interaction energy was found to increase in magnitude with decreasing alkyl chain length at the Hartree−Fock level, although no trend was found to exist with increasing anionic radius. Correlations between melting point and interaction energy were investigated. Linear trends were found to exist in the 1-n-butyl-3-methylimidazolium (Bmim) halide series as well as the 1-alkyl-3-methylimidazolium iodide series.

Leadership development as an intervention in occupational health psychology

Abstract: A growing body of literature suggests that organizational leadership is linked to a wide variety of employee outcomes, both positive and negative, relevant to occupational health and safety. All organizations have individuals in a leadership role, but few researchers consider leadership training as an effective intervention. This may be because such studies are difficult to conduct and because the target, being the employees, is indirect. In this paper for the special edition of Work & Stress, we review studies linking leadership to individual well-being and safety in organizations. These include studies concerning leadership style, abusive supervision and organizational fairness. We highlight intervention studies that suggest that these linkages are causal and that leadership development, usually in the form of training, is an effective intervention in occupational health psychology. It is proposed that leadership development should be a main target for research on interventions in Occupational ...

Managing Soil Microorganisms to Improve Productivity of Agro-Ecosystems

Abstract: Historically, agricultural production has relied on practices designed to manage nutrients, water, weeds, and crop diseases. Precision agriculture and integrated pest management programs have gone one step further by recognizing the need to target inputs where they are required in the field. The major objective of these programs has been to minimize adverse environmental impacts of intensive agriculture practices and reduce per unit production costs. This review surveys the literature, examining the manipulation of microbial (primarily bacterial) populations as linked to agricultural production, and discusses new approaches that involve the precision management of microorganisms in the agro-ecosystem. It is proposed that our understanding of plant–soil interactions can be greatly refined through the development of “smart” field technology, where real-time, computer-controlled electronic diagnostic devices can be used to monitor rhizosphere and plant health. We submit that “smart field” generated informati...