La pertinencia de la historia en la enseñanza de ciencias : argumentos y contraargumentos

Adding up to the debate about the possibility of a historical view in science teaching, the present article frames some responses to the criticisms that, on the basis of the need of simplification and reconstruction of history, object its intrusion in science education. In that sense, the essentially constructive character of history and, particularly, of history of science is appointed, where the epistemological position of the historian acquires special relevance. The multiplicity of historical stories is a constituent characteristic of history and, thus, it does not represent an obstacle in sciences teaching

Interior penalty discontinuous Galerkin FEM for the p(x)p(x)-Laplacian

In this paper we construct an "Interior Penalty" Discontinuous Galerkin method to approximate the minimizer of a variational problem related to the $p(x)-$Laplacian. The function $p:\Omega\to [p_1,p_2]$ is log H\"{o}lder continuous and $1<p_1\leq p_2<\infty$. We prove that the minimizers of the discrete functional converge to the solution. We also make some numerical experiments in dimension one to compare this method with the Conforming Galerkin Method, in the case where $p_1$ is close to one. This example is motivated by its applications to image processing.Comment: 26 pages, 2 figure

Strategies for improving peptide stability and delivery

Peptides play an important role in many fields, including immunology, medical diagnostics, and drug discovery, due to their high specificity and positive safety profile. However, for their delivery as active pharmaceutical ingredients, delivery vectors, or diagnostic imaging molecules, they suffer from two serious shortcomings: their poor metabolic stability and short half-life. Major research efforts are being invested to tackle those drawbacks, where structural modifications and novel delivery tactics have been developed to boost their ability to reach their targets as fully functional species. The benefit of selected technologies for enhancing the resistance of peptides against enzymatic degradation pathways and maximizing their therapeutic impact are also reviewed. Special note of cell-penetrating peptides as delivery vectors, as well as stapled modified peptides, which have demonstrated superior stability from their parent peptides, are reported

Large amounts of optically-obscured star formation in the host galaxies of some type-2 quasars

We present Hubble Space Telescope images, and spectral energy distributions from optical to infrared wavelengths for a sample of six 0.3<z<0.8 type-2 quasars selected in the mid-infrared using data from the Spitzer Space Telescope. All the host galaxies show some signs of disturbance. Most seem to possess dusty, star-forming disks. The disk inclination, estimated from the axial ratio of the hosts, correlates with the depth of the silicate feature in the mid-infrared spectra, implying that at least some of the reddening towards the AGN arises in the host galaxy. The star formation rates in these objects, as inferred from the strengths of the PAH features and far-infrared continuum, range from 3-90 Msun/yr, but are mostly much larger than those inferred from the [OII]3727 emission line luminosity, due to obscuration. Taken together with studies of type-2 quasar hosts from samples selected in the optical and X-ray, this is consistent with previous suggestions that two types of extinction processes operate within the type-2 quasar population, namely a component due to the dusty torus in the immediate environment of the AGN, and a more extended component due to a dusty, star forming disk.Comment: 5 pages, 3 figures. Accepted by ApJ Letter

Poly Spotlight Control

When this project began, The Cambria Center for the Arts Theater used a manually-operated spotlight. The sound created by the fans, along with the sheer size of the spotlight, required that it be housed in an attic room above the theater and shined through a closed window. This trapped a lot of heat in the room and involved some risk with climbing into and out of the attic room. This project sought to remedy those issues by mounting a pair of newer LED spotlights inside the theater. Doing this required a method for remotely controlling and actuating the angular position of each spotlight in two axes. Over the course of one year, the Dynalux team researched, designed, and built a solution to CCAT’s problem. The process by which they completed those steps is written in detail within this report. The first third of the year was spent in research and development. The team compared commercial and industry options to determine the best practices and designs. Many of the available options were too complicated or expensive and this reiterated that a cheaper and easier system was needed. At this point, Team Dynalux came up with a preliminary design that met all the design constraints. The next third of the year was dedicated to detailed analysis and proving that the design would work as intended. This included looking at all aspects of the system from motor torque requirements to strength and material properties. At this stage, the design was presented to the sponsor and advisors to begin manufacturing. The remainder of the project consisted of manufacturing, assembling, and testing. Some aspects had to be changed on-the-fly but the majority of the design remained the same throughout. Upon concluding machining and welding, the metal parts were finished and assembled with off-the-shelf components. When the mounts were complete, the electronics were added and tested in the overall system. Testing and manufacturing were time intensive but kept safety and reliability as the highest priority. The contents of this report are intended to document the process by which the project was completed but also provide reference to the parts and techniques used to build the system. Also included are comprehensive drawings and instructions to make sure the system is running smoothly, and if needed, provide maintenance

Neural computation as a tool for galaxy classification : methods and examples

We apply and compare various Artificial Neural Network (ANN) and other algorithms for automatic morphological classification of galaxies. The ANNs are presented here mathematically, as non-linear extensions of conventional statistical methods in Astronomy. The methods are illustrated using different subsets Artificial Neural Network (ANN) and other algorithms for automatic morphological classification of galaxies. The ANNs are presented here mathematically, as non-linear extensions of conventional statistical methods in Astronomy. The methods are illustrated using different subsets from the ESO-LV catalogue, for which both machine parameters and human classification are available. The main methods we explore are: (i) Principal Component Analysis (PCA) which tells how independent and informative the input parameters are. (ii) Encoder Neural Network which allows us to find both linear (PCA-like) and non-linear combinations of the input, illustrating an example of unsupervised ANN. (iii) Supervised ANN (using the Backpropagation or Quasi-Newton algorithms) based on a training set for which the human classification is known. Here the output for previously unclassified galaxies can be interpreted as either a continuous (analog) output (e.g. $T$-type) or a Bayesian {\it a posteriori} probability for each class. Although the ESO-LV parameters are sub-optimal, the success of the ANN in reproducing the human classification is 2 $T$-type units, similar to the degree of agreement between two human experts who classify the same galaxy images on plate material. We also examine the aspects of ANN configurations, reproducibility, scaling of input parameters and redshift information.Comment: uuencoded compressed postscript. The preprint is also available at http://www.ast.cam.ac.uk/preprint/PrePrint.htm