Hidden variables unseen by Random Forests

Random Forests are widely claimed to capture interactions well. However, some simple examples suggest that they perform poorly in the presence of certain pure interactions that the conventional CART criterion struggles to capture during tree construction. We argue that alternative partitioning schemes can enhance identification of these interactions. Furthermore, we extend recent theory of Random Forests based on the notion of impurity decrease by considering probabilistic impurity decrease conditions. Within this framework, consistency of a new algorithm coined 'Random Split Random Forest' tailored to address function classes involving pure interactions is established. In a simulation study, we validate that the modifications considered enhance the model's fitting ability in scenarios where pure interactions play a crucial role

Expression of ISG15, UBE1L and MX2 in white blood cells of early pregnant and bred-nonpregnant dairy cows

Abstract only availableIdentifying pregnant and nonpregnant cows shortly after insemination can improve reproductive efficiency in dairy cows if resynchronization is practiced on nonpregnant cows. Bovine Interferon Stimulated Gene Product 15 (ISG15), Bovine Ubiquitin-Activating E1-Like (UBE1L) Enzyme and MX2 are produced in response to conceptus-dervied interferon-τ. The objective was to determine the level of these mRNA in pregnant and bred-nonpregnant Holstein cows (n=14). We hypothesized that the amount of ISG15, UBE1L and MX2 mRNA would increase between d 14 to 20 in pregnant cows but not increase in bred-nonpregnant cows. Cows were synchronized to estrus and inseminated (d 0). Blood samples were collected on d 14, 16, 18 and 20 following insemination. Pregnancy status was determined at approximately 30 and 60 d after insemination. RNA was isolated, reverse transcribed into cDNA and amplified using quantitative RTPCR. Six cows were nonpregnant (open) and eight cows were pregnant on d 30. On d 60, four of the pregnant cows remained pregnant (pregnant-pregnant) and four were found open (aborted; pregnant-open). mRNA data were expressed as fold increase above control and relative to cyclophilin. A status by day interaction was detected for ISG15 (P<.001) and MX2 (P<.02). The interaction was not significant for UBE1L. Mean ISG15 and mean MX2 remained low for open cows, but increased markedly on d 18 and 20 in pregnant-pregnant cows. Pregnant-open cows either had low levels of ISG15 and MX2 or underwent an increase in ISG15 and MX2 on d 18 and 20. We conclude that ISG15, UBE1L and MX2 are differentially regulated in dairy cows during pregnancy recognition. ISG15 and MX2 mRNA expression could be used as an indicator of early pregnancy. Cows that abort their pregnancy after d 28 (pregnant-open) have abnormal ISG15 and MX2 mRNA expression between d 14 to 20.F.B. Miller Undergraduate Research Program in Animal Science

Glueball production in radiative J/psi, Upsilon decays

Using a bound-state model of weakly bound gluons for glueballs made of two gluons and a natural generalization of the perturbative QCD formalism for exclusive hadronic processes, we present results for glueball production in radiative J/psi, Upsilon decays into several possible glueball states, including L \not= 0 ones. We perform a detailed phenomenological analysis, presenting results for the more favored experimental candidates and for decay angular distributions.Comment: RevTeX4, 26 pages, 11 eps figure

Infrared Spectral Energy Distributions of Nearby Galaxies

The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multi-wavelength survey on a sample of 75 nearby galaxies. The 1-850um spectral energy distributions are presented using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally-integrated Spitzer data are generally consistent with the previous generation of models that were developed based on global data for normal star-forming galaxies, though significant deviations are observed. Spitzer's excellent sensitivity and resolution also allow a detailed investigation of the infrared spectral energy distributions for various locations within the three large, nearby galaxies NGC3031 (M81), NGC5194 (M51), and NGC7331. Strong correlations exist between the local star formation rate and the infrared colors f_nu(70um)/f_nu(160um) and f_nu(24um)/f_nu(160um), suggesting that the 24 and 70um emission are useful tracers of the local star formation activity level. Preliminary evidence indicates that variations in the 24um emission, and not variations in the emission from polycyclic aromatic hydrocarbons at 8um, drive the variations in the f_nu(8.0um)/f_nu(24um) colors within NGC3031, NGC5194, and NGC7331. If the galaxy-to-galaxy variations in spectral energy distributions seen in our sample are representative of the range present at high redshift then extrapolations of total infrared luminosities and star formation rates from the observed 24um flux will be uncertain at the factor-of-five level (total range). The corresponding uncertainties using the redshifted 8.0um flux (e.g. observed 24um flux for a z=2 source) are factors of 10-20. Considerable caution should be used when interpreting such extrapolated infrared luminosities.Comment: 32 pages including 16 figures; accepted for publication in the Astrophysical Journa

Contract Aware Components, 10 years after

The notion of contract aware components has been published roughly ten years ago and is now becoming mainstream in several fields where the usage of software components is seen as critical. The goal of this paper is to survey domains such as Embedded Systems or Service Oriented Architecture where the notion of contract aware components has been influential. For each of these domains we briefly describe what has been done with this idea and we discuss the remaining challenges.Comment: In Proceedings WCSI 2010, arXiv:1010.233

Hunting planets and observing disks with the JWST NIRCam coronagraph

The expected stable point spread function, wide field of view, and sensitivity of the NIRCam instrument on the James Webb Space Telescope (JWST) will allow a simple, classical Lyot coronagraph to detect warm Jovian-mass companions orbiting young stars within 150 pc as well as cool Jupiters around the nearest low-mass stars. The coronagraph can also be used to study protostellar and debris disks. At λ = 4.5 μm, where young planets are particularly bright relative to their stars, and at separations beyond ~0.5 arcseconds, the low space background gives JWST significant advantages over ground-based telescopes equipped with adaptive optics. We discuss the scientific capabilities of the NIRCam coronagraph, describe the technical features of the instrument, and present end-to-end simulations of coronagraphic observations of planets and circumstellar disks

Communications Biophysics

Contains reports on five research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-02

Diffractive point sets with entropy

After a brief historical survey, the paper introduces the notion of entropic model sets (cut and project sets), and, more generally, the notion of diffractive point sets with entropy. Such sets may be thought of as generalizations of lattice gases. We show that taking the site occupation of a model set stochastically results, with probabilistic certainty, in well-defined diffractive properties augmented by a constant diffuse background. We discuss both the case of independent, but identically distributed (i.i.d.) random variables and that of independent, but different (i.e., site dependent) random variables. Several examples are shown.Comment: 25 pages; dedicated to Hans-Ude Nissen on the occasion of his 65th birthday; final version, some minor addition

Defining the cognitive phenotype of autism

Although much progress has been made in determining the cognitive profile of strengths and weaknesses that characterise individuals with autism spectrum disorders (ASDs), there remain a number of outstanding questions. These include how universal strengths and deficits are; whether cognitive subgroups exist; and how cognition is associated with core autistic behaviours, as well as associated psychopathology. Several methodological factors have contributed to these limitations in our knowledge, including: small sample sizes, a focus on single domains of cognition, and an absence of comprehensive behavioural phenotypic information. To attempt to overcome some of these limitations, we assessed a wide range of cognitive domains in a large sample (N = 100) of 14- to 16-year-old adolescents with ASDs who had been rigorously behaviourally characterised. In this review, we will use examples of some initial findings in the domains of perceptual processing, emotion processing and memory, both to outline different approaches we have taken to data analysis and to highlight the considerable challenges to better defining the cognitive phenotype(s) of ASDs. Enhanced knowledge of the cognitive phenotype may contribute to our understanding of the complex links between genes, brain and behaviour, as well as inform approaches to remediation