Binary companions of evolved stars in APOGEE DR14: Orbital circularization

Short-period binary star systems dissipate orbital energy through tidal interactions that lead to tighter, more circular orbits. When at least one star in a binary has evolved off of the main sequence, orbital circularization occurs for longer-period (~100 day) systems. Past work by (Verbunt & Phinney 1995) has shown that the orbital parameters and the circularization periods of a small sample of binary stars with evolved-star members can be understood within the context of standard tidal circularization theory. Using a sample of binaries with subgiant, giant, and red clump star members that is nearly an order of magnitude larger, we reexamine predictions for tidal circularization of binary stars with evolved members. We confirm that systems predicted by equilibrium-tide theory to have circular orbits generally have negligible measured eccentricities. The circularization period is correlated with the surface gravity (i.e. size) of the evolved member, indicating that the circularization timescale must be shorter than the evolutionary timescale along the giant branch. A few exceptions to the conclusions above are mentioned in the discussion: Some of these exceptions are likely systems in which the spectrum of the secondary biases the radial velocity measurements, but four appear to be genuine, short-period, moderate-eccentricity systems.Comment: 13 pages, 6 figures; comments welcom

Implementation of a Hierarchical, Embedded, Cyber Attack Detection System for SPI Devices on Unmanned Aerial Systems

Unmanned Aerial Systems (UAS) create security concerns as their roles expand in commercial, military, and consumer spaces. The need to secure these systems is recognized in the architecture for a Hierarchical, Embedded, Cyber Attack Detection (HECAD) system. HECAD passively monitors the communication between a flight controller and all its peripherals like sensors and actuators. It ensures the functionality of a UAS is within the set of defined behavior and reports all potential problems, whether the errors were caused by cyber attacks or other physical faults. A portion of the design for Serial Peripheral Interface (SPI) devices on board a flight control system is developed on an FPGA device. A wide range of cyber attacks and other faults are checked in SPI HECAD, implemented with VHDL and verified through use of the Integrated Logic Analyzer tool

Professional 'imperialism' and resistance: social work in the Filippines

The sociology of professions has traditionally attempted to increase our understanding ofcategorisations of different occupations by reference to taxonomic hierarchies as well as theidentification and exploration of characteristics that warrant „professional status‟. In many cases, theseexplorations take the form of historical accounts of professional activity. Rarely however, has theliterature on professions explored processes of professionalization in developing, post-colonialcontexts. This article contributes to this body of literature in the study of professions in a number ofways. Firstly, it „maps‟ the growth of social work in the Philippines, placing this account within abroader discussion of social work as an international activity (Harrison & Melville, 2010; Lyons, 2006)and identifying some of the key forms and features of social work in the Philippines. Consideration isgiven to the degree of professionalisation of social work within the country by exploring professionalorganisation, regulation and education. In doing this, the article offers a critical overview of the natureand preoccupations of social work in the Philippines and celebrates the invaluable contributions itmakes to the country and its people.The article argues that the forms social work takes and the settings in which it happens reflect bothcontemporary societal and environmental factors as well as the global development of social work. Inthis sense, the article considers the impact of Roman Catholicism as well as the orientation of socialwork in relation to some enduring tensions and debates around the profession‟s purpose andpotential. Key to the professional form that social work takes in the Philippines is the contribution ofthe „indigenous‟ social work knowledge base which is explored, alongside a commentary on socialwork education and training in the country.The sociology of professions has traditionally attempted to increase our understanding of categorisations of different occupations by reference to taxonomic hierarchies, as well as the identification and exploration of characteristics that warrant 'professional status'. In may cases, this explorations take the forms of historical accounts of professional activity. Rarely, however, has the literature on professions explored processes of professionalization in devoliping, post-colonial contexts. This article contributes to this body of literature in the study of professions in a number of ways. Firstly, it 'maps' the growth of social work in the Filippines, placing this account within a broader discussions of social work as an internationality activity (Harrison & Melville, 2010; Lyons, 2006) and identifying some of the key forms and features of social work in the Filippines. Consideration is given to the degree of professionalisation of social work within the country by exploring professional organisation, regulation and education.  In doing this, the article offers a critical overview of the nature and preoccupations of social work in the Filippines and celebrates the invaluable contributions it makes to the country and its people. The article argue that the forms social work takes and the settings in wich it happens reflect both contemporay societal and environmental factors as well as the global development of social work.  In this sense, the article considers the impact of Roman Catholicism as well as the orientation of social work in relation to some enduring tensions and debates around the profession's purpose and potential. Key to the professional forms that social work takes in the Filippines is the contribution of 'indigenous' social work knowledge base wich is explored, alongside a comentary on social work education and training in the country.

Penn Teaches Resiliency: Proposal for a New Psychology-Based Academically Based Community Service Course

The University of Pennsylvania has a long legacy of advocating teaching styles and philosophies that engender democratic citizenship and civic engagement. In line with these central views of the University we wish to propose the creation of a new psychology academically based community service course called Penn Teaches Resiliency. This course will utilize the principles of problem solving learning to directly tackle the issue of depression in the West Philadelphia community. The research literature clearly highlights the alarming rates of depression found in low socioeconomic status, minority urban dwellers and we believe that offering this course is a key means by which Penn can help to reverse this trend. Penn Teaches Resiliency will utilize R4Power, an online resiliency intervention developed by psychologists intimately associated with the Penn Resiliency Project. There is already substantial student interest in such a course and Penn Teaches Resiliency would have numerous benefits for both the Penn and West Philadelphia communities. Multiple steps have already been taken in the creation of this class and we recommend that the Undergraduate Psychology Department maintain continued close communication and monitor pre-existing pilot programs in order to facilitate the course\u27s ultimate creation. We hope that creation of Penn Teaches Resiliency will prove to be a decisive first step in the improvement of mental health in the West Philadelphia community

Scalable and equivariant spherical CNNs by discrete-continuous (DISCO) convolutions

No existing spherical convolutional neural network (CNN) framework is both computationally scalable and rotationally equivariant. Continuous approaches capture rotational equivariance but are often prohibitively computationally demanding. Discrete approaches offer more favorable computational performance but at the cost of equivariance. We develop a hybrid discrete-continuous (DISCO) group convolution that is simultaneously equivariant and computationally scalable to high-resolution. While our framework can be applied to any compact group, we specialize to the sphere. Our DISCO spherical convolutions exhibit SO(3) rotational equivariance, where SO(n) is the special orthogonal group representing rotations in n-dimensions. When restricting rotations of the convolution to the quotient space SO(3)/SO(2) for further computational enhancements, we recover a form of asymptotic SO(3) rotational equivariance. Through a sparse tensor implementation we achieve linear scaling in number of pixels on the sphere for both computational cost and memory usage. For 4k spherical images we realize a saving of 109 in computational cost and 104 in memory usage when compared to the most efficient alternative equivariant spherical convolution. We apply the DISCO spherical CNN framework to a number of benchmark dense-prediction problems on the sphere, such as semantic segmentation and depth estimation, on all of which we achieve the state-of-the-art performance

d1005+68: A New Faint Dwarf Galaxy in the M81 Group

We present the discovery of d1005+68, a new faint dwarf galaxy in the M81 Group, using observations taken with the Subaru Hyper Suprime-Cam. d1005+68's color-magnitude diagram is consistent with a distance of $3.98_{-0.43}^{+0.39}$ Mpc, establishing group membership. We derive an absolute $V$-band magnitude, from stellar isochrone fitting, of $M_{V} = -7.94_{-0.50}^{+0.38}$, with a half-light radius of $r_{h} = 188_{-41}^{+39}$ pc. These place d1005+68 within the radius-luminosity locus of Local Group and M81 satellites and among the faintest confirmed satellites outside the Local Group. Assuming an age of 12 Gyr, d1005+68's red giant branch is best fit by an isochrone of [Fe/H] $= -1.90 \pm 0.24$. It has a projected separation from nearby M81 satellite BK5N of only 5 kpc. As this is well within BK5N's virial radius, we speculate that d1005+68 may be a satellite of BK5N. If confirmed, this would make d1005+68 one of the first detected satellites-of-a-satellite.Comment: 7 pages, 4 figures, 1 table, additional affiliations include

Managing the matrix: decadal responses of eucalypt-dominated savanna to ambient fire regimes

Much of our understanding of the response of savanna systems to fire disturbance relies on observations derived from manipulative fire plot studies. Equivocal findings from both recent Australian and African savanna fire plot assessments have significant implications for informing conservation management and reliable estimation of biomass stocks and dynamics. Influential northern Australian replicated fire plot studies include the 24-year plot-scale Munmarlary and the five-year catchment-scale Kapalga, mesic savanna ( . 1000 mm/yr of rainfall) experiments in present-day Kakadu National Park. At Munmarlary, under low-to-moderate-intensity fire treatments, woody vegetation dominated by mature eucalypts was found to be structurally stable. At Kapalga, substantial declines in woody biomass were observed under more intense fire treatments, and modeling assessments implicate early-season fires as having adverse effects on longer-term tree recruitment. Given these contrasting perspectives, here we take advantage of a landscape-scale fire response monitoring program established on three major northern Australian conservation reserves (Kakadu, Litchfield, and Nitmiluk National Parks). Using statistical modeling we assess the decadal effects of ambient fire regime parameters (fire frequency, severity, seasonality, time since fire) on 32 vegetation structure components and abundance of 21 tree and 16 grass species from 122 monitoring plots. Over the study period the mean annual frequency of burning of plots was 0.53, comprising mostly early-dry-season, low-severity fires. Structural and species responses were variable but often substantial, notably resulting in stem recruitment and declines in juveniles, but only weakly explained by fire regime and habitat variables. Modeling of these observations under three realistic scenarios (increased fire severity under projected worsening climate change; modest and significant reductions in fire frequency to meet conservation criteria) indicates that all scenarios have positive and negative structural implications. Effecting significant regional fire regime change (e.g., reduction in frequency and size of severe fires) is demonstrably feasible, but it incurs risks and potentially some undesirable structural consequences. Given recent Australian and African experience, the generality and application of landscape-scale implications derived from manipulative fire assessments (including variable grazing and browsing regimes) in savanna require more critical assessment