Dark/Visible Parallel Universes and Big Bang Nucleosynthesis

We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.Comment: Invited talk at the Workshops "CompStar: the physics and astrophysics of compact stars", Tahiti, June 4-8, 2012, "New Directions in Nuclear Astrophysics", Castiglion Fiorentino, Italy, June 18-22, 2012, and "Carpathian Summer School of Physics", Sinaia, Romania, June 24 - July 7, 2012. To be published in AIP Proceeding

Processing and characterization of a polypropylene biocomposite compounded with maleated and acrylated compatibilizers

Polypropylene (PP) biocomposites containing 20wt.% sunflower hull as a particulate reinforcement were compounded and tested under tensile, flexural, and impact loadings. The incorporation of the sunflower hull without compatibilizer resulted in diminished tensile strength and impact energy absorption but increased flexural strength and both tensile modulus and flexural modulus when compared to neat PP. Formulations containing three different chemical compatibilizers were tested to determine their effectiveness in improving the interfacial adhesion between the fiber surface and PP chains. Maleic anhydride grafted with PP (MA-g-PP) achieved greater improvements in tensile strength but reduced impact strength in comparison to an acrylic-acid-grafted PP compatibilizer (AA-g-PP). The molecular weight, graft level, and the ability to affect strength, modulus, and absorbed impact energy were also investigated for the compatibilizers. A MA-g-PP having high molecular weight and low graft level was most effective in improving the investigated properties of a sunflower hull-reinforced polypropylene biocomposite

State of the Humanities 2021: Workforce & Beyond

How should one measure the value of a college degree? In recent years, policy-makers have focused their attention on earnings as the primary measure of the value of a degree, often using that metric to single out humanities degrees as less valuable than others. But there are other—less tangible—measures of value, such as satisfaction with one's work and life more generally, that might also be applied to these discussions.Without taking a position on which metrics are best, this report, based largely on original research commissioned by the American Academy of Arts and Sciences' Humanities Indicators, examines a variety of outcome measures, including graduates' satisfaction with their jobs, their finances, and their lives generally. The evidence shows that humanities graduates tend to earn less and have slightly higher levels of unemployment than business majors and graduates from some STEM fields. With respect to perceived well-being, however, humanities majors are similar to graduates from almost every other field. The data cannot explain the seeming disparity between the objective and subjective measures, but they provide a starting point for a more nuanced discussion about the relationship among fields of undergraduate study, employment, and quality of life. And for faculty, the report also points to a potential area of concern regarding the way they communicate to students about the skills developed in the course of an education in the field, as a substantial share of humanities graduates perceive little or no relationship between their job and their degree. The data were all gathered prior to the COVID-19 pandemic, but past experience tracking this sort of data for the humanities—particularly through the Great Recession—gives us little reason to expect a significant shift in values over the medium term

State of the Humanities 2022: From Graduate Education to the Workforce

Given the recent decline in students earning bachelor's degrees in the humanities, a great deal of concern is focused on undergraduate education. But many of the questions received by the Humanities Indicators staff have to do with outcomes for those who earn a graduate degree in the field. This report explores several key topics related to graduate education, including degree trends, the demographics of degree recipients, the extent to which programs engage students in career preparation activities, and graduates' career outcomes. The report relies heavily on the high-quality data collected by the U.S. Department of Education's National Center for Education Statistics, and also the National Science Foundation's National Center for Science and Engineering Statistics, several of whose surveys yield valuable information about graduate degree holders in the humanities.The findings include a few surprises: 1) while most of the attention in the disciplines seems to focus on PhDs, the field conferred almost five times as many master's as doctoral degrees in recent years; 2) even so, the number of master's degrees conferred annually in the humanities has been in decline over the past several years and their share of all master's and professional degrees reached a historic low in 2020; 3) the number of humanities PhDs awarded each year was at a near-record high in 2020, but as a share of all doctoral degrees, they fell to a historic low; 4) while the academic job market for humanities PhDs has been depressed since 2008, there is no evidence that this is due to the substitution of adjunct for tenure-track positions; and 5) regardless of where they end up—either in academia or out—the large majority of graduate degree recipients in the humanities are satisfied with their jobs, despite earnings that are considerably lower than those of their counterparts from other fields.This report reflects the ongoing mission of the Humanities Indicators, a nationally recognized source of nonpartisan information about the field. The Indicators website covers 121 topics and includes more than 340 graphs detailing the state of the humanities in schools, higher education, and the workforce; levels of support for research and other key activities; and the role of the humanities in the day-to-day life of the nation. The project draws on data sources that meet the highest standards of social scientific rigor, relying heavily on the products of the U.S. federal statistical system

Large Deletions in the pAtC58 Megaplasmid of Agrobacterium tumefaciens Can Confer Reduced Carriage Cost and Increased Expression of Virulence Genes

The accessory plasmid pAtC58 of the common laboratory strain of Agrobacterium tumefaciens confers numerous catabolic functions and has been proposed to play a role in virulence. Genomic sequencing of evolved laboratory strains of A. tumefaciens revealed the presence of multiple deletion events in the At plasmid, with reductions in plasmid size ranging from 25% to 30% (115–194 kb). Flanking both ends of the sites of these deletions is a short-nucleotide repeat sequence that is in a single copy in the deleted plasmids, characteristic of a phage- or transposon-mediated deletion event. This repeat sequence is widespread throughout the C58 genome, but concentrated on the At plasmid, suggesting its frequency to be nonrandom. In this study, we assess the prevalence of the larger of these deletions in multiple C58 derivatives and characterize its functional significance. We find that in addition to elevating virulence gene expression, this deletion is associated with a significantly reduced carriage cost to the cell. These observations are a clear demonstration of the dynamic nature of the bacterial genome and suggest a mechanism for genetic plasticity of these costly but otherwise stable plasmids. Additionally, this phenomenon could be the basis for some of the dramatic recombination events so ubiquitous within and among megaplasmids

Evolution of the Insertion-Deletion Mutation Rate Across the Tree of Life

Citation: Sung, W., Ackerman, M. S., Dillon, M. M., Platt, T. G., Fuqua, C., Cooper, V. S., & Lynch, M. (2016). Evolution of the Insertion-Deletion Mutation Rate Across the Tree of Life. G3-Genes Genomes Genetics, 6(8), 2583-2591. doi:10.1534/g3.116.030890/-/DC1Mutations are the ultimate source of variation used for evolutionary adaptation, while also being predominantly deleterious and a source of genetic disorders. Understanding the rate of insertion-deletion mutations (indels) is essential to understanding evolutionary processes, especially in coding regions, where such mutations can disrupt production of essential proteins. Using direct estimates of indel rates from 14 phylogenetically diverse eukaryotic and bacterial species, along with measures of standing variation in such species, we obtain results that imply an inverse relationship of mutation rate and effective population size. These results, which corroborate earlier observations on the base-substitution mutation rate, appear most compatible with the hypothesis that natural selection reduces mutation rates per effective genome to the point at which the power of random genetic drift (approximated by the inverse of effective population size) becomes overwhelming. Given the substantial differences in DNA metabolism pathways that give rise to these two types of mutations, this consistency of results raises the possibility that refinement of other molecular and cellular traits may be inversely related to species-specific levels of random genetic drift

Breadth of Vaccinated Cancer Patient Humoral Response to SARS-CoV-2 Spike Protein and RBD Variants

SARS-CoV-2, the virus responsible for the COVID-19 of which several variants have emerged, such as the B.1.351 SARS-CoV-2 variant. The Receptor Binding Domain (RBD), located within the Spike protein is an immunogenic epitope for potent neutralizing antibodies. Current mRNA vaccines encode for the Spike protein, allowing the body to build antigen-specific antibodies. Assays measuring protective antibodies are essential to manage the COVID-19 pandemic and can be used as a platform for variant screening. RBD-foldon 2.2 is a novel antigen produced by fusing RBD with the trimerization domain Fibritin from Bacteriophage T4. Its amino acid sequence is based on the original Wuhan strain. (Breckenridge, 2021). B.1.351 RBD-foldon 2.2 antigen is identical to RBD-foldon 2.2, except it uses the B.1.351 variant RBD sequence. Using cancer patient sera samples, the breadth and robustness of response was examined in comparison to patients that indicated “no chronic conditions”. We hypothesized there would be a difference in humoral response to RBD-variant antigens in COVID-19 vaccinated cancer patients undergoing treatment vs patients with no chronic conditions. For sample selection, cancer patients were age/sex matched to individuals with no underlying health conditions, that received the same mRNA vaccine within 2 weeks of each other. To quantify antibody levels, ELISA end-point titers were performed. ELISAs detected levels of IgG and IgA antibodies against Spike, RBD-foldon, RBD-foldon 2.2, and RBD-foldon B.1.351. (Bushau, 2021). The statistical analysis used was a two-tailed student’s t-test to compare mean value of end-point titers between experimental and control groups. No significant difference between experimental and control groups for any antibody-antigen combination. B.1.351 RBD-foldon appears to elicit a lower response than RBD-foldon 2.2. Lower response may be explained by the mRNA sequence used in current vaccines encodes for original Wuhan SARS-CoV-2 spike protein. The platform is predictive of the level of antibody protection for variant screening

Analysis of phosphatases in ER-negative breast cancers identifies DUSP4 as a critical regulator of growth and invasion.

Estrogen receptor (ER)-negative cancers have a poor prognosis, and few targeted therapies are available for their treatment. Our previous analyses have identified potential kinase targets critical for the growth of ER-negative, progesterone receptor (PR)-negative and HER2-negative, or "triple-negative" breast cancer (TNBC). Because phosphatases regulate the function of kinase signaling pathways, in this study, we investigated whether phosphatases are also differentially expressed in ER-negative compared to those in ER-positive breast cancers. We compared RNA expression in 98 human breast cancers (56 ER-positive and 42 ER-negative) to identify phosphatases differentially expressed in ER-negative compared to those in ER-positive breast cancers. We then examined the effects of one selected phosphatase, dual specificity phosphatase 4 (DUSP4), on proliferation, cell growth, migration and invasion, and on signaling pathways using protein microarray analyses of 172 proteins, including phosphoproteins. We identified 48 phosphatase genes are significantly differentially expressed in ER-negative compared to those in ER-positive breast tumors. We discovered that 31 phosphatases were more highly expressed, while 11 were underexpressed specifically in ER-negative breast cancers. The DUSP4 gene is underexpressed in ER-negative breast cancer and is deleted in approximately 50 % of breast cancers. Induced DUSP4 expression suppresses both in vitro and in vivo growths of breast cancer cells. Our studies show that induced DUSP4 expression blocks the cell cycle at the G1/S checkpoint; inhibits ERK1/2, p38, JNK1, RB, and NFkB p65 phosphorylation; and inhibits invasiveness of TNBC cells. These results suggest that that DUSP4 is a critical regulator of the growth and invasion of triple-negative breast cancer cells