791 research outputs found
Forecasting US Army Enlistment Contract Production in Complex Geographical Marketing Areas
Purpose: The purpose of this paper is to demonstrate an improved method for forecasting the US Army recruiting. Design/methodology/approach: Time series methods, regression modeling, principle components and marketing research are included in this paper. Findings: This paper found the unique ability of multiple statistical methods applied to a forecasting context to consider the effects of inputs that are controlled to some degree by a decision maker. Research limitations/implications: This work will successfully inform the US Army recruiting leadership on how this improved methodology will improve their recruitment process. Practical implications: Improved US Army analytical technique for forecasting recruiting goals
Biochemical and genetic analysis of Ecm14, a conserved fungal pseudopeptidase
© 2020, The Author(s). Background: Like most major enzyme families, the M14 family of metallocarboxypeptidases (MCPs) contains a number of pseudoenzymes predicted to lack enzyme activity and with poorly characterized molecular function. The genome of the yeast Saccharomyces cerevisiae encodes one member of the M14 MCP family, a pseudoenzyme named Ecm14 proposed to function in the extracellular matrix. In order to better understand the function of such pseudoenzymes, we studied the structure and function of Ecm14 in S. cerevisiae. Results: A phylogenetic analysis of Ecm14 in fungi found it to be conserved throughout the ascomycete phylum, with a group of related pseudoenzymes found in basidiomycetes. To investigate the structure and function of this conserved protein, His6-tagged Ecm14 was overexpressed in Sf9 cells and purified. The prodomain of Ecm14 was cleaved in vivo and in vitro by endopeptidases, suggesting an activation mechanism; however, no activity was detectable using standard carboxypeptidase substrates. In order to determine the function of Ecm14 using an unbiased screen, we undertook a synthetic lethal assay. Upon screening approximately 27,000 yeast colonies, twenty-two putative synthetic lethal clones were identified. Further analysis showed many to be synthetic lethal with auxotrophic marker genes and requiring multiple mutations, suggesting that there are few, if any, single S. cerevisiae genes that present synthetic lethal interactions with ecm14Δ. Conclusions: We show in this study that Ecm14, although lacking detectable enzyme activity, is a conserved carboxypeptidase-like protein that is secreted from cells and is processed to a mature form by the action of an endopeptidase. Our study and datasets from other recent large-scale screens suggest a role for Ecm14 in processes such as vesicle-mediated transport and aggregate invasion, a fungal process that has been selected against in modern laboratory strains of S. cerevisiae
Individual differences in envy experienced through perspective-taking involves functional connectivity of the superior frontal gyrus
Envy is the painful or resentful awareness of another’s advantage combined with a desire to possess that same advantage. Recent neuroscientific research has begun to shed light on the brain regions that process the experience of envy, including regions of the prefrontal cortex involved in emotional processing and social cognition. It is still unclear, however, which regions of the brain are functionally connected during the experience of envy. We recorded functional neuroimaging data while inducing simulated envy in participants, experienced through a perspective-taking hypothetical scenario task. In this task, participants took the perspective of a protagonist portrayed in a written description and compared themselves to either i) a self-similar/superior individual, ii) a self-dissimilar/superior individual, or iii) a self-dissimilar/average individual. During each comparison, participants also reported how much envy they experienced while taking the protagonists perspective. We demonstrate an inverse relationship in the connectivity of the left superior frontal gyrus to both the right supramarginal gyrus and the precuneus with respect to self-reported envy ratings across participants. In other words, we show that the greater the functional connectivity that the left superior frontal gyrus shares with the right supramarginal gyrus and precuneus, the less reported envy a participant experiences. Overall, our results are in line with previous research implicating the superior frontal gyrus in the reappraisal of negative emotions and extend these findings by showing this region is also involved in modulating the simulated experience of the social comparative, negative emotion of envy
Helmholtz bright and boundary solitons
We report, for the first time, exact analytical boundary solitons of a generalized cubic-quintic Non-Linear Helmholtz (NLH) equation. These solutions have a linked-plateau topology that is distinct from conventional dark soliton solutions; their amplitude and intensity distributions are spatially delocalized and connect regions of finite and zero wave-field disturbances (suggesting also the classification as 'edge solitons'). Extensive numerical simulations compare the stability properties of recently-reported Helmholtz bright solitons, for this type of polynomial non-linearity, to those of the new boundary solitons. The latter are found to possess a remarkable stability characteristic, exhibiting robustness against perturbations that would otherwise lead to the destabilizing of their bright-soliton counterpart
Korteweg-de Vries description of Helmholtz-Kerr dark solitons
A wide variety of different physical systems can be described by a relatively small set of universal equations. For example, small-amplitude nonlinear Schrödinger dark solitons can be described by a Korteweg-de Vries (KdV) equation. Reductive perturbation theory, based on linear boosts and Gallilean transformations, is often employed to establish connections to and between such universal equations. Here, a novel analytical approach reveals that the evolution of small-amplitude Helmholtz–Kerr dark solitons is also governed by a KdV equation. This broadens the class of nonlinear systems that are known to possess KdV soliton solutions, and provides a framework for perturbative analyses when propagation angles are not negligibly small. The derivation of this KdV equation involves an element that appears new to weakly nonlinear analyses, since transformations are required to preserve the rotational symmetry inherent to Helmholtz-type equations
- …