BELIEVING IN ACHIEVING: EXAMINING AFRICAN AMERICAN WOMEN’S DOCTORAL ATTAINMENT

This research explored the intersectionality of race, class, and gender within the sources of self-efficacy (Bandura, 1997) underlying the socialization messages influencing African American women’s doctoral attainment beliefs. Twenty African American female/woman doctoral achievers completed an online survey, consisting of open-ended and multiple-choice response items, designed to identify and explore the sources of self-efficacy influencing African American women’s doctoral attainment beliefs. Eleven participants participated in focus interviews to expand upon and clarify initial survey responses. Thematic analysis (Braun & Clarke, 2006) and tenets of critical race theory (Ladson-Billings & Tate, 1995; McCoy & Rodricks, 2015) were used to analyze the sources of self-efficacy and the intersectionality of race, class, and gender within the socialization messages identified by participants as influencing their doctoral attainment beliefs. Among the sources of self-efficacy, participants frequently described vicarious experiences (co-op and internship opportunities) and social persuasions from family, friends, and faculty as influencing doctoral attainment beliefs. The following themes were identified as salient in shaping African American women’s doctoral attainment beliefs: 1) a voice at the table; 2) faith; and 3) experiential knowledge and support. Findings from this study illuminate the salience of doctoral attainment beliefs to African American women’s doctoral pursuit and attainment. Recommendations and implications for African American women’s doctoral program retentionand completion are discussed

Looking for Evidence of the TFW Virus

On an almost daily basis I am confronted with stories or examples of people disengaged at work, or stories of managers who are frustrated by their inability to engage employees. In many cases, work simply is not working. Researchers at the ISEOR Institute in France have identified a root cause of organizational dysfunction they have worked with throughout Europe and Latin America that may explain some of the flaws of the modern workplace. ISEOR researchers have determined that management ideology is largely based on the modern interpretation of three proponents of scientific management; Taylor, Fayol, and Weber. Thus they named this ideological flaw the TFW Virus. This was an interpretive case study seeking to discover if management practices of American organizations reveal and transmit the TFW Virus. The study took place at Manufacturing Corp., a high tech business in the Pacific Northwest of the United States and included interviews with 19 individuals in middle management and line worker positions. In the study I found that the workers did express that they experienced depersonalization and a need to submit to the organization at work. Additionally, I found the four elements of the virus; an aristocratic view, apathy, separation, and massification. While this study may not be applicable to other organizations, it does indicate clearly that there is value in looking at the ideological influences of American management to determine if there are foundational flaws leading to organizations that are inhumane and unproductive. Even in a very successful American organization where people reported they were happy the elements of the virus were easy to find, indicating that that virus may be prevalent throughout organizations in America

Intrinsically-disordered N-termini in human parechovirus 1 capsid proteins bind encapsidated RNA

Human parechoviruses (HPeV) are picornaviruses with a highly-ordered RNA genome contained within icosahedrally-symmetric capsids. Ordered RNA structures have recently been shown to interact with capsid proteins VP1 and VP3 and facilitate virus assembly in HPeV1. Using an assay that combines reversible cross-linking, RNA affinity purification and peptide mass fingerprinting (RCAP), we mapped the RNA-interacting regions of the capsid proteins from the whole HPeV1 virion in solution. The intrinsically-disordered N-termini of capsid proteins VP1 and VP3, and unexpectedly, VP0, were identified to interact with RNA. Comparing these results to those obtained using recombinantly-expressed VP0 and VP1 confirmed the virion binding regions, and revealed unique RNA binding regions in the isolated VP0 not previously observed in the crystal structure of HPeV1. We used RNA fluorescence anisotropy to confirm the RNA-binding competency of each of the capsid proteins’ N-termini. These findings suggests that dynamic interactions between the viral RNA and the capsid proteins modulate virus assembly, and suggest a novel role for VP0.Peer reviewe

Structure-Transport relationship in organized soft matter systems by diffusion NMR

In this paper we demonstrate and discuss the potentials of pulsed field gradient nuclear magnetic resonance (PFG NMR) at high magnetic field and high magnetic field gradients for uncovering the relationship between the structural and transport properties of soft matter systems. The reported diffusion studies are focused on room temperature ionic liquids and their mixtures with carbon dioxide or water as well as on multicomponent lipid bilayers. Both types of systems exhibit a well-defined structural organization on various length scales. Our experimental approach allows correlating this structural organization with the transport properties. The diffusion data were obtained by proton and carbon-13 PFG NMR. The experimental studies were in some cases complemented by dynamic Monte Carlo simulations

Spatial regulation of MCAK promotes cell polarization and focal adhesion turnover to drive robust cell migration

The asymmetric distribution of microtubule (MT) dynamics in migrating cells is important for cell polarization, yet the underlying regulatory mechanisms remain underexplored. Here, we addressed this question by studying the role of the MT depolymerase, MCAK (mitotic centromere-associated kinesin), in the highly persistent migration of RPE-1 cells. MCAK knockdown leads to slowed migration and poor directional movement. Fixed and live cell imaging revealed that MCAK knockdown results in excessive membrane ruffling as well as defects in cell polarization and the maintenance of a major protrusive front. Additionally, loss of MCAK increases the lifetime of focal adhesions by decreasing their disassembly rate. These functions correlate with a spatial distribution of MCAK activity, wherein activity is higher in the trailing edge of cells compared with the leading edge. Overexpression of Rac1 has a dominant effect over MCAK activity, placing it downstream of or in a parallel pathway to MCAK function in migration. Together, our data support a model in which the polarized distribution of MCAK activity and subsequent differential regulation of MT dynamics contribute to cell polarity, centrosome positioning, and focal adhesion dynamics, which all help facilitate robust directional migration

Stoichiometric incorporation of base substitutions at specific sites in supercoiled DNA and supercoiled recombination intermediates

Supercoiled DNA is the relevant substrate for a large number of DNA transactions and has additionally been found to be a favorable form for delivering DNA and protein-DNA complexes to cells. We report here a facile method for stoichiometrically incorporating several different modifications at multiple, specific, and widely spaced sites in supercoiled DNA. The method is based upon generating an appropriately gapped circular DNA, starting from single-strand circular DNA from two phagemids with oppositely oriented origins of replication. The gapped circular DNA is annealed with labeled and unlabeled synthetic oligonucleotides to make a multiply nicked circle, which is covalently sealed and supercoiled. The method is efficient, robust and can be readily scaled up to produce large quantities of labeled supercoiled DNA for biochemical and structural studies. We have applied this method to generate dye-labeled supercoiled DNA with heteroduplex bubbles for a Förster resonance energy transfer (FRET) analysis of supercoiled Holliday junction intermediates in the λ integrative recombination reaction. We found that a higher-order structure revealed by FRET in the supercoiled Holliday junction intermediate is preserved in the linear recombination product. We suggest that in addition to studies on recombination complexes, these methods will be generally useful in other reactions and systems involving supercoiled DNA

Selection of bacteriophage λ integrases with altered recombination specificity by in vitro compartmentalization

In vitro compartmentalization (IVC) was employed for the first time to select for novel bacteriophage λ integrase variants displaying significantly enhanced recombination activity on a non-cognate target DNA sequence. These variants displayed up to 9-fold increased recombination activity over the parental enzyme, and one mutant recombined the chosen non-cognate substrate more efficiently than the parental enzyme recombined the wild-type DNA substrate. The in vitro specificity phenotype extended to the intracellular recombination of episomal vectors in HEK293 cells. Surprisingly, mutations conferring the strongest phenotype do not occur in the λ integrase core-binding domain, which is known to interact directly with cognate target sequences. Instead, they locate to the N-terminal domain which allosterically modulates integrase activity, highlighting a previously unknown role for this domain in directing integrase specificity. The method we describe provides a robust, completely in vitro platform for the development of novel integrase reagent tools for in vitro DNA manipulation and other biotechnological applications

The 22q11.2 region regulates presynaptic gene-products linked to schizophrenia

How the 22q11.2 deletion predisposes to psychiatric disease is unclear. Here, the authors examine living human neuronal cells and show that 22q11.2 regulates the expression of genes linked to autism during early development, and genes linked to schizophrenia and synaptic biology in neurons. It is unclear how the 22q11.2 deletion predisposes to psychiatric disease. To study this, we generated induced pluripotent stem cells from deletion carriers and controls and utilized CRISPR/Cas9 to introduce the heterozygous deletion into a control cell line. Here, we show that upon differentiation into neural progenitor cells, the deletion acted in trans to alter the abundance of transcripts associated with risk for neurodevelopmental disorders including autism. In excitatory neurons, altered transcripts encoded presynaptic factors and were associated with genetic risk for schizophrenia, including common and rare variants. To understand how the deletion contributed to these changes, we defined the minimal protein-protein interaction network that best explains gene expression alterations. We found that many genes in 22q11.2 interact in presynaptic, proteasome, and JUN/FOS transcriptional pathways. Our findings suggest that the 22q11.2 deletion impacts genes that may converge with psychiatric risk loci to influence disease manifestation in each deletion carrier.Peer reviewe

New Applications for Phage Integrases

Within the last twenty-five years bacteriophage integrases have rapidly risen to prominence as genetic tools for a wide range of applications from basic cloning to genome engineering. Serine integrases such as that from ϕC31 and its relatives have found an especially wide-range of applications within diverse micro-organisms right through to multi-cellular eukaryotes. Here we review the mechanisms of the two major families of integrases, the tyrosine and serine integrases, and the advantages and disadvantages of each type as they are applied in genome engineering and synthetic biology. In particular, we focus on the new areas of metabolic pathway construction and optimisation, bio-computing, heterologous expression and multiplexed assembly techniques. Integrases are versatile and efficient tools that can be used in conjunction with the various extant molecular biology tools to streamline the synthetic biology production line