Reflecting on Fifty Years of Progress for Women in Science

Like young women today, 50 years ago I too assumed that gender discrimination in science was a thing of the past. Girls who grew up in America in the Sputnik era, as I did, were encouraged to become scientists. By 1964, when I graduated from college with a major in biology, I thought it entirely possible I’d win a Nobel prize. Why not? Dorothy Hodgkin won one that year. At Harvard, my professors had strongly encouraged me to go to graduate school. When I finished my postdoc in 1973, I was actively recruited to the MIT faculty. What were those feminists complaining about

Testing Convolutional Neural Networks for finding strong gravitational lenses in KiDS

Convolutional Neural Networks (ConvNets) are one of the most promising methods for identifying strong gravitational lens candidates in survey data. We present two ConvNet lens-finders which we have trained with a dataset composed of real galaxies from the Kilo Degree Survey (KiDS) and simulated lensed sources. One ConvNet is trained with single \textit{r}-band galaxy images, hence basing the classification mostly on the morphology. While the other ConvNet is trained on \textit{g-r-i} composite images, relying mostly on colours and morphology. We have tested the ConvNet lens-finders on a sample of 21789 Luminous Red Galaxies (LRGs) selected from KiDS and we have analyzed and compared the results with our previous ConvNet lens-finder on the same sample. The new lens-finders achieve a higher accuracy and completeness in identifying gravitational lens candidates, especially the single-band ConvNet. Our analysis indicates that this is mainly due to improved simulations of the lensed sources. In particular, the single-band ConvNet can select a sample of lens candidates with $\sim40\%$ purity, retrieving 3 out of 4 of the confirmed gravitational lenses in the LRG sample. With this particular setup and limited human intervention, it will be possible to retrieve, in future surveys such as Euclid, a sample of lenses exceeding in size the total number of currently known gravitational lenses.Comment: 16 pages, 10 figures. Accepted for publication in MNRA

Non-Gaussian velocity distributions in excited granular matter in the absence of clustering

The velocity distribution of spheres rolling on a slightly tilted rectangular two dimensional surface is obtained by high speed imaging. The particles are excited by periodic forcing of one of the side walls. Our data suggests that strongly non-Gaussian velocity distributions can occur in dilute granular materials even in the absence of significant density correlations or clustering. When the surface on which the particles roll is tilted further to introduce stronger gravitation, the collision frequency with the driving wall increases and the velocity component distributions approach Gaussian distributions of different widths.Comment: 4 pages, 5 figures. Additional information at http://physics.clarku.edu/~akudrolli/nls.htm

Polymers pushing Polymers: Polymer Mixtures in Thermodynamic Equilibrium with a Pore

We investigate polymer partitioning from polymer mixtures into nanometer size cavities by formulating an equation of state for a binary polymer mixture assuming that only one (smaller) of the two polymer components can penetrate the cavity. Deriving the partitioning equilibrium equations and solving them numerically allows us to introduce the concept of "polymers-pushing-polymers" for the action of non-penetrating polymers on the partitioning of the penetrating polymers. Polymer partitioning into a pore even within a very simple model of a binary polymer mixture is shown to depend in a complicated way on the composition of the polymer mixture and/or the pore-penetration penalty. This can lead to enhanced as well as diminished partitioning, due to two separate energy scales that we analyse in detail.Comment: 10 pages, 6 figure

Advanced chronic liver disease in the last year of life: a mixed methods study to understand how care in a specialist liver unit could be improved

Objective: To identify the limitations in palliative care provision in the last year of life for people with liver cirrhosis and potential barriers to and enablers of palliative care. / Design: Mixed methods, including a retrospective case note review, qualitative focus groups and individual interviews. / Setting: A tertiary referral liver centre in the south of England (UK). / Participants: Purposively selected case notes of 30 people with cirrhosis who attended the tertiary referral liver centre and died during an 18-month period; a purposive sample of 22 liver health professionals who participated in either focus groups or individual interviews. / Primary and secondary outcomes: Data collected from case notes included hospital admissions, documented discussions of prognosis and palliative care provision. Qualitative methods explored management of people with cirrhosis, and barriers to and enablers of palliative care. / Results: Participants had high rates of hospital admissions and symptom burden. Clinicians rarely discussed prognosis or future care preferences; they lacked the skills and confidence to initiate discussions. Palliative care provision occurred late because clinicians were reluctant to refer due to their perception that reduced liver function is reversible, poor understanding of the potential of a palliative approach; palliative care was perceived negatively by patients and families. / Conclusions: People dying with cirrhosis have unpredictable trajectories, but share a common pathway of frequent admissions and worsening symptoms as death approaches. The use of clinical tools to identify the point of irreversible deterioration and joint working between liver services and palliative care may improve care for people with cirrhosis

High precision spectra at large redshift for dynamical DE cosmologies

The next generation mass probes will investigate DE nature by measuring non-linear power spectra at various z, and comparing them with high precision simulations. Producing a complete set of them, taking into account baryon physics and for any DE state equation w(z), would really be numerically expensive. Regularities reducing such duty are essential. This paper presents further n-body tests of a relation we found, linking models with DE state parameter w(z) to const.-w models, and also tests the relation in hydro simulations.Comment: PASCOS 2010, the 16th International Symposium on Particles, Strings and Cosmology, Valencia (Spain), July 19th - 23rd, 201

Reusable Agena study. Volume 2: Technical

The application of the existing Agena vehicle as a reusable upper stage for the space shuttle is discussed. The primary objective of the study is to define those changes to the Agena required for it to function in the reusable mode in the 100 percent capture of the NASA-DOD mission model. This 100 percent capture is achieved without use of kick motors or stages by simply increasing the Agena propellant load by using optional strap-on-tanks. The required shuttle support equipment, launch and flight operations techniques, development program, and cost package are also defined

The Effects of an AGN on Host Galaxy Colour and Morphology Measurements

We assess the effects of simulated active galactic nuclei (AGNs) on the colour and morphology measurements of their host galaxies. To test the morphology measurements, we select a sample of galaxies not known to host AGNs and add a series of point sources scaled to represent specified fractions of the observed V band light detected from the resulting systems; we then compare morphology measurements of the simulated systems to measurements of the original galaxies. AGN contributions >20 per cent bias most of the morphology measurements tested, though the extent of the apparent bias depends on the morphological characteristics of the original galaxies. We test colour measurements by adding to non-AGN galaxy spectra a quasar spectrum scaled to contribute specified fractions of the rest-frame B band light detected from the resulting systems. A quasar fraction of 5 per cent can move the NUV-r colour of an elliptical galaxy from the UV-optical red sequence to the green valley, and 20 per cent can move it into the blue cloud. Combining the colour and morphology results, we find that a galaxy/AGN system with an AGN contribution >20 per cent may appear bluer and more bulge-dominated than the underlying galaxy. We conclude that (1) bulge-dominated, E/S0/Sa, and early-type morphology classifications are accurate for red AGN host galaxies and may be accurate for blue host galaxies, unless the AGN manifests itself as a well-defined point source; and (2) although highly unobscured AGNs, such as the quasar used for our experiments, can significantly bias the measured colours of AGN host galaxies, it is possible to identify such systems by examining optical images of the hosts for the presence of a point source and/or measuring the level of nuclear obscuration.Comment: 18 pages, 19 figures, 1 table. Accepted for publication in MNRA

Galaxy Clusters in the IRAC Dark Field II: Mid-IR Sources

We present infrared luminosities, star formation rates, colors, morphologies, locations, and AGN properties of 24 micron-detected sources in photometrically detected high-redshift clusters in order to understand the impact of environment on star formation and AGN evolution in cluster galaxies. We use three newly-identified z=1 clusters selected from the IRAC dark field; the deepest ever mid-IR survey with accompanying, 14 band multiwavelength data including deep HST imaging and deep wide-area Spitzer MIPS 24 micron imaging. We find 90 cluster members with MIPS detections within two virial radii of the cluster centers, of which 17 appear to have spectral energy distributions dominated by AGN and the rest dominated by star formation. We find that 43 of the star forming are luminous infrared galaxies (LIRGs). The majority of sources (81%) are spirals or irregulars. A large fraction (at least 25%) show obvious signs of interactions. The MIPS -detected member galaxies have varied spatial distributions as compared to the MIPS-undetected members with one of the three clusters showing SF galaxies being preferentially located on the cluster outskirts, while the other 2 clusters show no such trend. Both the AGN fraction and the summed SFR of cluster galaxies increases from z=0 to 1, at a rate that is a few times faster in clusters than over the same redshift range in the field. Cluster environment does have an effect on the evolution of both AGN fraction and SFR from redshift one to the present, but does not effect the infrared luminosities or morphologies of the MIPS sample. Star formation happens in the same way regardless of environment making MIPS sources look the same in the cluster and field, however the cluster environment does encourage a more rapid evolution with time as compared to the field.Comment: 18 pages, 9 figures, ApJ accepte