Analysis of Mutator activity in embryogenic callus cultures and regenerated plants of Zea mays L.

Activity of the Mutator transposable element system in maize was assessed in tissue cultures and regenerated plants by Southern analysis of Mu-element modification status and genomic position. Examination of embryogenic callus cultures established from the F[subscript]1\u27s of crosses between active Mutator stock and maize inbreds A188 and H99 determined that the in planta parameters for Mutator activity were maintained in an in vitro environment. Subclonal populations from callus lines were used to demonstrate that Mu elements from active Mutator lines can remain transpositionally active in tissue culture systems. Novel Mu-homologous restriction fragments occurred in 38% of the subpopulations containing unmodified Mu elements, but not in control cultures containing modified Mu elements. The high mutagenic potential of Mutator should prove useful for in vitro mutagenesis, selection, and transposon tagging schemes, and should serve to enhance the generation of useful somaclonal variants in regenerated plants;Investigation of Mutator activity in regenerated plants demonstrated the maintenance of Mutator activity in progeny of plants regenerated from an active Mutator callus line. Activity was detected genetically by the segregation for new mutant phenotypes and molecularly by the appearance of Mu-homologous restriction fragments novel to the regenerant progeny. Segregation for new seedling mutations in third- and fourth-generation regenerant progeny of a callus culture derived from an inactive (Mu-loss) line suggests that a low-level reactivation of Mutator activity occurred in these progeny plants;Possible tissue- or development-specific influences on Mu-element excision were also explored. Embryogenic and endosperm cultures were established from maize lines in which Mu elements were known to have inserted at particular endosperm and aleurone reporter loci (wx-Mum1 and bz-Mum8). Somatic instability was demonstrated phenotypically at both mutant loci in endosperm callus tissues, indicating that excision occurs in endosperm (and aleurone) in vitro as well as in planta. Southern analysis of wx-Mum1 and bz-Mum8 embryogenic lines produced no evidence of Mu-element excision from either locus. Further studies involving tissue comparisons detected differences in Mu-element modification and genomic position in various tissues of H99/Mu[superscript]2 regenerated plants. Absence of Mu-homologous restriction fragments in a particular tissue relative to other tissues of the same plant implied that Mu-element excision occurred. Together, these findings provide preliminary evidence that Mu-element excision may be subject to tissue-specific influence or regulation

Detours and Syncopations: in Search of Lost Time Through the Lens of Les Intermittences du Coeur

Les Intermittences du coeur, a section of Sodom and Gomorrah in Marcel Proust\u27s In Search of Lost Time, exposes the raw work of molirning that the Search spirals in on again and again. The section, in which the Narrator through the workings of involuntary memory confronts the stark reality of the loss of his grandmother, recapitulates in both substance and rhythm the counterpoint of many of the central forces of the Search: those of absence and presence, death and survival, isolation and contextualization, unification and fragmentation, dispersal and concentration, the boundaried self and the hazily boundaried consciousness. Les Intermittences sets a clearly expressed contrapuntal precedent for the rest of the novel, in the Narrator\u27s intense experience of two contradictory states at once and in its tracing of emotional and intellectual lapses, inconstancies, alternations, and mutations. Les Intermittences becomes a focal point of motif and energy for the Narrator and his creator, offering us a possibly privileged, though not necessarily cleanly paradigmatic, glimpse at Proust\u27s double-helix thematics

Exploring Difficult Truths and the Possibility of Healing and Transformation through the Art of Norman Rockwell and Samuel Bak

Racism remains a pervasive problem in society. Beyond iconic photographs that capture a distinct moment in history that prompt reflection on racism, art can be a powerful prompt to encourage society to reflect on this persistent difficult truth. Norman Rockwell and Samuel Bak reconfigured highly recognized photographs into portraits with the intention to explore questions about racism. The photographs and the art they inspired feature a single child in the midst of surrounding racism. Through the use of these images, Rockwell and Bak move audiences beyond the immediate consideration of racism, toward healing, and to future transformation

Geometric and combinatorial properties of extended Springer fibers

We consider a generalization of the Springer resolution studied in earlier work of the authors, called the extended Springer resolution. In type $A$, this map plays a role in Lusztig's generalized Springer correspondence comparable to that of the Springer resolution in the Springer correspondence. The fibers of the Springer resolution play a key part in the latter story, and connect the combinatorics of tableaux to geometry. Our main results prove the same is true for fibers of the extended Springer resolution -- their geometry is governed by the combinatorics of tableaux. In particular, we prove that these fibers are paved by affines, up to the action of a finite group, and give combinatorial formulas for their Betti numbers. This yields, among other things, a simple formula for dimensions of stalks of the Lusztig sheaves arising in the study of the generalized Springer correspondence, and shows that there is a close resemblance between each Lusztig sheaf and the Springer sheaf for a smaller group.Comment: 37 pages, 2 figure

More than an Anniversary - A preview of William Frantz Public School: A Story of Race, Resistance, Resiliency, and Recovery in New Orleans

William Frantz Public School: A Story of Race, Resistance, Resiliency, and Recovery in New Orleans will be released by Peter Lang in 2020. The book examines issues related to public education through events at the iconic William Frantz Public School, one of the first New Orleans public schools to be desegregated in 1960. The book covers important topics such as the resegregation of public schools, systemic racism, poverty, school accountability movements, and proliferatoin of charter schools

A New Orleans community center rises from its ugly history as a segregated school

They were known as “the McDonogh Three,” and unlike many stories of the tumultuous civil rights era, this one has a hopeful ending. On May 4, 2022, Leona Tate, Gail Etienne and Tessie Prevost are scheduled to cut the ribbons around the front door of the former McDonogh 19 Elementary School. Located in New Orleans’ Lower 9th Ward, the school was the scene of some of the nation’s fiercest anti-integration school battles in the early 1960s. Now named after the three women, the school has been transformed into the TEP Center, whose name consists of the first letters of each woman’s last name. It has been redesigned to include affordable housing and exhibition space focused on the civil rights era and the three women’s stories

The Legacy of William Frantz Public School: Commemoration vs. Celebration

Sixty years ago, Ruby Bridges, a Black first-grade student, entered the all-White William Frantz Public School (WFPS). Her entry into WFPS represented a massive transformation in public education in the United States and embedded the school in the U.S. civil rights movement. Fifteen years ago, following Hurricane Katrina, the rapid increase in charter schools in New Orleans centered WFPS in a second transformation, the movement to reform public education. In addition to these two seminal events, a more complete history of WFPS provides justification that these landmark transformations be commemorated rather than celebrated