Navigating the Turbulent Waters of School Reform Guided by Complexity Theory

The goal of this research study has been to develop, implement, and evaluate a school reform design experiment at a continuation high school with low-income, low-performing underrepresented minority students. The complexity sciences served as a theoretical framework for this design experiment. Treating an innovative college preparatory program as a nested complex adaptive system within a larger complex adaptive system, the school, we used features of complex adaptive systems (equilibrium, emergence, self-organization, and feedback loops) as a framework to design a strategy for school reform. The goal was to create an environment for change by pulling the school far from equilibrium using a strategy we call “purposeful perturbations” to disrupt the stable state of the school in a purposeful way. Over the four years of the study, several tipping points were reached, and we developed agent-based simulation models that capture important dynamic properties of the reform at these points. The study draws upon complexity theory in multiple ways that have supported improved education for low-achieving students

Oxygen Absorption in Cooling Flows

The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of the galaxy, NGC 1399, the group, NGC 5044, and the cluster, A1795. These systems have amongst the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below ~0.4 keV the most reasonable model for the absorber is warm, collisionally ionized gas with T=10^{5-6} K where ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT, and also is consistent with the negligible atomic and molecular H inferred from HI, and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified by Chandra, XMM, and ASTRO-E.Comment: 4 pages (2 figures), Accepted for publication in ApJ Letters, no significant changes from previous submitted versio

Weak plaquette valence bond order in the S=1/2S=1/2 honeycomb J1−J2J_1-J_2 Heisenberg model

Using the density matrix renormalization group, we investigate the $S=1/2$ Heisenberg model on the honeycomb lattice with first- ($J_1$) and second-neighbor ($J_2$) interactions. We are able to study long open cylinders with widths up to 12 lattice spacings. For $J_2/J_1$ near 0.3, we find an apparently paramagnetic phase, bordered by an antiferromagnetic phase for $J_2\lesssim 0.26$ and by a valence bond crystal for $J_2\gtrsim 0.36$. The longest correlation length that we find in this intermediate phase is for plaquette valence bond (PVB) order. This correlation length grows strongly with cylinder circumference, indicating either quantum criticality or weak PVB order.Comment: 9 pages, 15 figures, minor changes are made for publication in Phys. Rev. Let

Genome-wide patterns of polymorphism in an inbred line of the African malaria mosquito Anopheles gambiae.

Anopheles gambiae is a major mosquito vector of malaria in Africa. Although increased use of insecticide-based vector control tools has decreased malaria transmission, elimination is likely to require novel genetic control strategies. It can be argued that the absence of an A. gambiae inbred line has slowed progress toward genetic vector control. In order to empower genetic studies and enable precise and reproducible experimentation, we set out to create an inbred line of this species. We found that amenability to inbreeding varied between populations of A. gambiae. After full-sib inbreeding for ten generations, we genotyped 112 individuals--56 saved prior to inbreeding and 56 collected after inbreeding--at a genome-wide panel of single nucleotide polymorphisms (SNPs). Although inbreeding dramatically reduced diversity across much of the genome, we discovered numerous, discrete genomic blocks that maintained high heterozygosity. For one large genomic region, we were able to definitively show that high diversity is due to the persistent polymorphism of a chromosomal inversion. Inbred lines in other eukaryotes often exhibit a qualitatively similar retention of polymorphism when typed at a small number of markers. Our whole-genome SNP data provide the first strong, empirical evidence supporting associative overdominance as the mechanism maintaining higher than expected diversity in inbred lines. Although creation of A. gambiae lines devoid of nearly all polymorphism may not be feasible, our results provide critical insights into how more fully isogenic lines can be created

Unexpected z-Direction Ising Antiferromagnetic Order in a frustrated Spin-1/2 J1−J2J_1-J_2 XY Model on the Honeycomb Lattice

Using the density matrix renormalization group (DMRG) on wide cylinders, we study the phase diagram of the spin-1/2 XY model on the honeycomb lattice, with first-neighbor ($J_1 = 1$) and frustrating second-neighbor ($J_2>0$) interactions. For the intermediate frustration regime $0.22\lesssim J_2\lesssim0.36$, we find a surprising antiferromagnetic Ising phase, with ordered moments pointing along the z axis, despite the absence of any S_z_z interactions in the Hamiltonian. Surrounding this phase as a function of $J_2$ are antiferromagnetic phases with the moments pointing in the $x-y$ plane for small $J_2$ and a close competition between an $x-y$ plane magnetic collinear phase and a dimer phase for large values of $J_2$. We do not find any spin liquid phases in this model.Comment: 5 pages, 5 figures, minor changes made for publication on PR

Martin Heidegger and the First World War

The subtitle of this work is “Being and Time as Funeral Oration.” This addition helps a reader to appreciate that the book functions on various levels: scholarly, to the extent that it offers a reading of selected details in Heidegger’s first major work; historical, in that Altman asserts with great vigor that Being and Time should be seen as a “funeral oration” for those who died in World War One; biographical, in that we read much about Heidegger’s personal actions in political and academic contexts leading to and during both WWI and a decade after the conclusion of the “Great War”; psychological, in recurring speculation aimed at what was happening causally and emotively in Heidegger’s mind when he made certain practical decisions or wrote certain texts; autobiographical, in that the reader frequently learns how the author feels concerning many of the subjects discussed or mentioned in this work; and unabashedly normative: for Altman, Heidegger, “the Nazi philosopher” (64) and “little magician of Messkirch” (198, also 283), is a “liar” (109, 269, 281), a “shirker and malingerer” (256), “in denial” (263 fn25), a “guilty sinner” (268), “shameless” (272) and the “guiltiest of men” (283)— indeed, Altman concludes that Martin Heidegger “...cannot and must no longer remain Germany’s last great philosopher” (286—the book’s final words)

Heidegger and Jewish Thought: Difficult Others

This work is an anthology of fourteen articles on various aspects of Heidegger’s relation to the Jews and, more abstractly, what it means to be Jewish. The essays are arranged under three headings—Heidegger Thinks the Jews, Heidegger and Jewish Thinkers, Heidegger and Jewish Thought. The work also includes an introduction by Elad Lapidot and, as an appendix, Thomas Sheehan’s bibliography of Heidegger’s works (including English translations as of 2017). Lapidot’s introduction highlights the stimulus for the anthology, the publication of Heidegger’s “so-called Black Notebooks,” notes for the years 1931 to 1948. For Lapidot, “about a dozen passages” contain “strong anti-Jewish statements”; the result: “It is not only Heidegger who is on trial now, but his entire heritage, everything that inspired him and that he inspired, an entire intellectual tradition”—in sum, this controversy “manifests a real event of thought” (2)

Wittgenstein: The Fate of Wonder Wittgenstein’s Critique of Metaphysics and Modernity

That Ludwig Wittgenstein (1889–1951) was one of the most influential twentieth-century philosophers is hardly a controversial claim. However, Wittgenstein’s own works, principally the Tractatus Logico-Philosophicus (1922) and Philosophical Investigations (1953; second edition 1997), have engendered a considerable range of widely diverse—and divisive—commentary. In The Fate of Wonder Wittgenstein’s Critique of Metaphysics and Modernity, Kevin M. Cahill has produced a useful and at times provocative addition to this literature

Philosophers in Search of Life...

If, after reading the above title, someone has ventured this far—the opening sentence—then he or she has doubtless conquered any urge to dismiss the contents of this piece (and do something else...) because the title is so blatantly silly. Onlya philosopher would be so sadly quixotic as to feel a need to become involved in a “search” for life. Dwelling in the realm of the living is where we humans spend all our waking hours. Furthermore, all of us settle into sleep for a greater or lesser amount of time and once in that state (discounting the differentiating factor of dreams), we exhibit the practical necessity of rest and a general quieting of the demands of consciousness—remaining alive throughout. Life is everywhere. What point would be served by identifying it as an object of philosophical interest and concern