William Barton Rogers and the Idea of MIT

Winner, 2009 Outstanding Book Award, History of Education SocietyWinner, 2009 Richard Slatten Prize for Excellence in Virginia Biography, Virginia Historical SocietyConceptual founder of the Massachusetts Institute of Technology, William Barton Rogers was a highly influential scientific mind and educational reformer of the nineteenth century. A. J. Angulo recounts the largely unknown story of one man's ideas and how they gave way to the creation of one of America’s premier institutions of higher learning. MIT's long tradition of teaching, research, and technological innovation for real-world applications is inexorably linked to Rogers’ educational philosophy. Emphasizing the “useful arts”—a curriculum of specialized scientific study stressing theory and practice, innovation and functionality—Rogers sought to revolutionize standard educational practices of the day. Controversial in an era typified by a generalist approach to teaching the sciences, Rogers’ model is now widely emulated by institutions throughout the world. Exploring the intersection of Rogers' educational philosophy and the rise of technical institutes in America, this biography offers a long-overdue account of the man behind MIT

Well-posedness and stability results for the Gardner equation

In this article we present local well-posedness results in the classical Sobolev space H^s(R) with s > 1/4 for the Cauchy problem of the Gardner equation, overcoming the problem of the loss of the scaling property of this equation. We also cover the energy space H^1(R) where global well-posedness follows from the conservation laws of the system. Moreover, we construct solitons of the Gardner equation explicitly and prove that, under certain conditions, this family is orbitally stable in the energy space.Comment: 1 figure. Accepted for publication in Nonlin.Diff Eq.and App

High Gain Amplifier with Enhanced Cascoded Compensation

A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT) the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated using a 0.5 μm technology, resulting, for a load of 45 pF and supply voltage of 1.65 V, in open-loop-gain of 129 dB, 23 MHz of gain-bandwidth product, 60o phase margin, 675 μW power consumption and 1% settling time of 28 ns

Ultra Low-Power Analog Median Filters

The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used

Constraining Anisotropic Baryon Oscillations

We present an analysis of anisotropic baryon acoustic oscillations and elucidate how a mis-estimation of the cosmology, which leads to incorrect values of the angular diameter distance, d_A, and Hubble parameter, H, manifest themselves in changes to the monopole and quadrupole power spectrum of biased tracers of the density field. Previous work has focused on the monopole power spectrum, and shown that the isotropic "dilation" combination d_A^2/H is robustly constrained by an overall shift in the scale of the baryon feature. We extend this by demonstrating that the quadrupole power spectrum is sensitive to an anisotropic "warping" mode d_A H, allowing one to break the degeneracy between d_A and H. We describe a method for measuring this warping, explicitly marginalizing over the form of redshift space distortions. We verify this method on N-body simulations and estimate that d_A H can be measured with a fractional accuracy of ~ 3/sqrt(V) % where the survey volume is estimated in (Gpc/h)^3.Comment: 4 pages, 2 fig

Lymphotoxins and cytomegalovirus cooperatively induce interferon-beta, establishing host-virus détente

Tumor necrosis factor (TNF)-related cytokines regulate cell death and survival and provide strong selective pressures for viruses, such as cytomegalovirus (CMV), to evolve counterstrategies in order to persist in immune-competent hosts. Signaling by the lymphotoxin (LT)-β receptor or TNF receptor-1, but not Fas or TRAIL receptors, inhibits the cytopathicity and replication of human CMV by a nonapoptotic, reversible process that requires nuclear factor κB (NF-κB)-dependent induction of interferon-β (IFN-β). Efficient induction of IFN-β requires virus infection and LT signaling, demonstrating the need for both host and viral factors in the curtailment of viral replication without cellular elimination. LTα-deficient mice and LTβR-Fc transgenic mice were profoundly susceptible to murine CMV infection. Together, these results reveal an essential and conserved role for LTs in establishing host defense to CMV

Measuring resilience to economic shocks: an application to Spain

In this paper, we evaluate Spanish regions’ resistance to the economic crisis under three main resilience notions: “adaptative, ” “engineering” and “ecological.” “Adaptative” resilience is measured through a traditional shift-share approach applied to employment, whereas “engineering” and “ecological” resilience pay attention to growth path and total employment level, in the pre- and post-crisis period. The paper presents an application of the different notion of resilience to the case of Spanish provinces in the last years. We find that provinces with sectoral structure and location advantages, or those with locational advantages in the post-crisis period (according to the “adaptative” resilience measure), exhibit a significantly lower “drop” in growth (according to the “engineering” and “ecological” resilience measure). Furthermore, we conclude that the probability of presenting a better behavior (lower “drop” in growth than the average) increases for those regions specialized in the service sector before the crisis. As expected, the worse behavior has correspond to those regions specialized in the pre-crisis period in the construction sector