1,594 research outputs found
Understanding the Role of Relationship Maintenance in Enduring Couple Partnerships in Later Adulthood
Intimate relationships in later adulthood are understudied despite their positive association with health and well-being. This cross-sectional mixed methods study sought to redress this gap by investigating relationship maintenance in later adulthood. Our international sub-sample comprised 1,565 participants aged 55 + and in an ongoing relationship. Results from hierarchical multiple regression indicated that overall happiness with the relationship had the largest effect size on relationship maintenance, with 53% of the variance explained. Content analyses of open-ended questions identified companionship and laughter as some of the “best liked” aspects of the relationship. Housework/cooking and saying “I love you” were among the behaviors that made participants feel appreciated. Results illustrated the types of maintenance behaviors adults in later adulthood who are in enduring partnerships employ
Digital cartography of Io
A high resolution controlled mosaic of the hemisphere of Io centered on longitude 310 degrees is produced. Digital cartographic techniques were employed. Approximately 80 Voyager 1 clear and blue filter frames were utilized. This mosaic was merged with low-resolution color images. This dataset is compared to the geologic map of this region. Passage of the Voyager spacecraft through the Io plasma torus during acquisition of the highest resolution images exposed the vidicon detectors to ionized radiation, resulting in dark-current buildup on the vidicon. Because the vidicon is scanned from top to bottom, more charge accumulated toward the bottom of the frames, and the additive error increases from top to bottom as a ramp function. This ramp function was removed by using a model. Photometric normalizations were applied using the Minnaert function. An attempt to use Hapke's photometric function revealed that this function does not adequately describe Io's limb darkening at emission angles greater than 80 degrees. In contrast, the Minnaert function accurately describes the limb darkening up to emission angles of about 89 degrees. The improved set of discrete camera angles derived from this effort will be used in conjunction with the space telemetry pointing history file (the IPPS file), corrected on 4 or 12 second intervals to derive a revised time history for the pointing of the Infrared Interferometric Spectrometer (IRIS). For IRIS observations acquired between camera shutterings, the IPPS file can be corrected by linear interpolation, provided that the spacecraft motions were continuous. Image areas corresponding to the fields of view of IRIS spectra acquired between camera shutterings will be extracted from the mosaic to place the IRIS observations and hotspot models into geologic context
Rings and spirals in barred galaxies. I Building blocks
In this paper we present building blocks which can explain the formation and
properties both of spirals and of inner and outer rings in barred galaxies. We
first briefly summarise the main results of the full theoretical description we
have given elsewhere, presenting them in a more physical way, aimed to an
understanding without the requirement of extended knowledge of dynamical
systems or of orbital structure. We introduce in this manner the notion of
manifolds, which can be thought of as tubes guiding the orbits. The dynamics of
these manifolds can govern the properties of spirals and of inner and outer
rings in barred galaxies. We find that the bar strength affects how unstable
the L1 and L2 Lagrangian points are, the motion within the 5A5A5Amanifold tubes
and the time necessary for particles in a manifold to make a complete turn
around the galactic centre. We also show that the strength of the bar, or, to
be more precise, of the non-axisymmetric forcing at and somewhat beyond the
corotation region, determines the resulting morphology. Thus, less strong bars
give rise to R1 rings or pseudorings, while stronger bars drive R2, R1R2 and
spiral morphologies. We examine the morphology as a function of the main
parameters of the bar and present descriptive two dimensional plots to that
avail. We also derive how the manifold morphologies and properties are modified
if the L1 and L2 Lagrangian points become stable. Finally, we discuss how
dissipation affects the manifold properties and compare the manifolds in
gas-like and in stellar cases. Comparison with observations, as well as clear
predictions to be tested by observations will be given in an accompanying
paper.Comment: Typos corrected to match the version in press in MNRA
Indians: Modern Tribal Jurisdiction over Non-Indian Parties: The Supreme Court Takes Another Bite Out of Tribal Sovereignty in \u3ci\u3eStrate v. A-1 Contractors\u3c/i\u3e
Justifications in Constraint Handling Rules for Logical Retraction in Dynamic Algorithms
We present a straightforward source-to-source transformation that introduces
justifications for user-defined constraints into the CHR programming language.
Then a scheme of two rules suffices to allow for logical retraction (deletion,
removal) of constraints during computation. Without the need to recompute from
scratch, these rules remove not only the constraint but also undo all
consequences of the rule applications that involved the constraint. We prove a
confluence result concerning the rule scheme and show its correctness. When
algorithms are written in CHR, constraints represent both data and operations.
CHR is already incremental by nature, i.e. constraints can be added at runtime.
Logical retraction adds decrementality. Hence any algorithm written in CHR with
justifications will become fully dynamic. Operations can be undone and data can
be removed at any point in the computation without compromising the correctness
of the result. We present two classical examples of dynamic algorithms, written
in our prototype implementation of CHR with justifications that is available
online: maintaining the minimum of a changing set of numbers and shortest paths
in a graph whose edges change.Comment: Pre-proceedings paper presented at the 27th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur,
Belgium, 10-12 October 2017 (arXiv:1708.07854
EffectiveSan: Type and Memory Error Detection using Dynamically Typed C/C++
Low-level programming languages with weak/static type systems, such as C and
C++, are vulnerable to errors relating to the misuse of memory at runtime, such
as (sub-)object bounds overflows, (re)use-after-free, and type confusion. Such
errors account for many security and other undefined behavior bugs for programs
written in these languages. In this paper, we introduce the notion of
dynamically typed C/C++, which aims to detect such errors by dynamically
checking the "effective type" of each object before use at runtime. We also
present an implementation of dynamically typed C/C++ in the form of the
Effective Type Sanitizer (EffectiveSan). EffectiveSan enforces type and memory
safety using a combination of low-fat pointers, type meta data and type/bounds
check instrumentation. We evaluate EffectiveSan against the SPEC2006 benchmark
suite and the Firefox web browser, and detect several new type and memory
errors. We also show that EffectiveSan achieves high compatibility and
reasonable overheads for the given error coverage. Finally, we highlight that
EffectiveSan is one of only a few tools that can detect sub-object bounds
errors, and uses a novel approach (dynamic type checking) to do so.Comment: To appear in the Proceedings of 39th ACM SIGPLAN Conference on
Programming Language Design and Implementation (PLDI2018
Quantum statistics on graphs
Quantum graphs are commonly used as models of complex quantum systems, for
example molecules, networks of wires, and states of condensed matter. We
consider quantum statistics for indistinguishable spinless particles on a
graph, concentrating on the simplest case of abelian statistics for two
particles. In spite of the fact that graphs are locally one-dimensional, anyon
statistics emerge in a generalized form. A given graph may support a family of
independent anyon phases associated with topologically inequivalent exchange
processes. In addition, for sufficiently complex graphs, there appear new
discrete-valued phases. Our analysis is simplified by considering combinatorial
rather than metric graphs -- equivalently, a many-particle tight-binding model.
The results demonstrate that graphs provide an arena in which to study new
manifestations of quantum statistics. Possible applications include topological
quantum computing, topological insulators, the fractional quantum Hall effect,
superconductivity and molecular physics.Comment: 21 pages, 6 figure
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