1,104 research outputs found
Understanding the effects of time perspective: A meta-analysis testing a self-regulatory framework
Despite extensive evidence that time perspective is associated with a range of important outcomes across a variety of life domains (e.g., health, education, wealth), the question of why time perspective has such wide-reaching effects remains unknown. The present review proposes that self-regulatory processes can offer insight into why time perspective is linked to outcomes. To test this idea we classified measures of time perspective according to the dimension of time perspective that they reflected (e.g., past, present-hedonistic, future) and measures of self-regulation according to the self-regulatory process (i.e., goal setting, goal monitoring, and goal operating), ability, or outcome that they reflected. A systematic search identified 378 studies, reporting 2,000 tests of the associations between measures of time perspective and self-regulation. Random-effects meta-analyses with robust variance estimation found that a future time perspective had small-to-medium-sized positive associations with goal setting (r+ = 0.25), goal monitoring (r+ = 0.19), goal operating (r+ = 0.24), self-regulatory ability (r+ = 0.35), and outcomes (r+ = 0.18). Present time perspective, including being present-hedonistic and present-fatalistic, was negatively associated with self-regulatory processes, ability, and outcomes (r+ ranged from â0.00 to â0.27). Meta-analytic mediation models found that the relationship between future time perspective and outcomes was mediated by goal monitoring, goal operating, and self-regulatory ability, but not goal setting. As the first test of why time perspective is associated with key outcomes, the findings highlight the central role of self-regulation processes and abilities for understanding why people with certain time perspectives experience better outcomes
Fourier Analysis of Gapped Time Series: Improved Estimates of Solar and Stellar Oscillation Parameters
Quantitative helio- and asteroseismology require very precise measurements of
the frequencies, amplitudes, and lifetimes of the global modes of stellar
oscillation. It is common knowledge that the precision of these measurements
depends on the total length (T), quality, and completeness of the observations.
Except in a few simple cases, the effect of gaps in the data on measurement
precision is poorly understood, in particular in Fourier space where the
convolution of the observable with the observation window introduces
correlations between different frequencies. Here we describe and implement a
rather general method to retrieve maximum likelihood estimates of the
oscillation parameters, taking into account the proper statistics of the
observations. Our fitting method applies in complex Fourier space and exploits
the phase information. We consider both solar-like stochastic oscillations and
long-lived harmonic oscillations, plus random noise. Using numerical
simulations, we demonstrate the existence of cases for which our improved
fitting method is less biased and has a greater precision than when the
frequency correlations are ignored. This is especially true of low
signal-to-noise solar-like oscillations. For example, we discuss a case where
the precision on the mode frequency estimate is increased by a factor of five,
for a duty cycle of 15%. In the case of long-lived sinusoidal oscillations, a
proper treatment of the frequency correlations does not provide any significant
improvement; nevertheless we confirm that the mode frequency can be measured
from gapped data at a much better precision than the 1/T Rayleigh resolution.Comment: Accepted for publication in Solar Physics Topical Issue
"Helioseismology, Asteroseismology, and MHD Connections
Two Mathematically Equivalent Versions of Maxwell's Equations
This paper is a review of the canonical proper-time approach to relativistic
mechanics and classical electrodynamics. The purpose is to provide a physically
complete classical background for a new approach to relativistic quantum
theory. Here, we first show that there are two versions of Maxwell's equations.
The new version fixes the clock of the field source for all inertial observers.
However now, the (natural definition of the effective) speed of light is no
longer an invariant for all observers, but depends on the motion of the source.
This approach allows us to account for radiation reaction without the
Lorentz-Dirac equation, self-energy (divergence), advanced potentials or any
assumptions about the structure of the source. The theory provides a new
invariance group which, in general, is a nonlinear and nonlocal representation
of the Lorentz group. This approach also provides a natural (and unique)
definition of simultaneity for all observers. The corresponding particle theory
is independent of particle number, noninvariant under time reversal (arrow of
time), compatible with quantum mechanics and has a corresponding positive
definite canonical Hamiltonian associated with the clock of the source.
We also provide a brief review of our work on the foundational aspects of the
corresponding relativistic quantum theory. Here, we show that the standard
square-root and the Dirac equations are actually two distinct
spin- particle equations.Comment: Appeared: Foundations of Physic
CCL2 and CCR2 regulate pain-related behaviour and early gene expression in post-traumatic murine osteoarthritis but contribute little to chondropathy
SummaryObjectiveThe role of inflammation in structural and symptomatic osteoarthritis (OA) remains unclear. One key mediator of inflammation is the chemokine CCL2, primarily responsible for attracting monocytes to sites of injury. We investigated the role of CCL2 and its receptor CCR2 in experimental OA.DesignOA was induced in 10 weeks old male wild type (WT), Ccl2â/â and Ccr2â/â mice, by destabilisation of the medial meniscus (DMM). RNA was extracted from whole joints at 6Â h and 7 days post-surgery and examined by reverse transcription polymerase chain reaction (RT-PCR). Gene expression changes between naĂŻve and DMM-operated mice were compared. Chondropathy scores, from mice at 8, 12, 16 and 20 weeks post DMM were calculated using modified Osteoarthritis Research Society International (OARSI) grading systems. Changes in hind paw weight distribution, as a measure of pain, were assessed by Linton incapacitance.ResultsAbsence of CCL2 strongly suppressed (>90%) selective inflammatory response genes in the joint 6Â h post DMM, including arginase 1, prostaglandin synthase 2, nitric oxide synthase 2 and inhibin A. IL6, MMP3 and tissue inhibitor of metalloproteinase 1 were also significantly suppressed. Similar trends were also observed in the absence of CCR2. A lower average chondropathy score was observed in both Ccl2â/â and Ccr2â/â mice at 12, 16 and 20 weeks post DMM compared with WT mice, but this was only statistically significant at 20 weeks in Ccr2â/â mice. Pain-related behaviour in Ccl2â/â and Ccr2â/â mice post DMM was delayed in onset.ConclusionThe CCL2/CCR2 axis plays an important role in the development of pain in murine OA, but contributes little to cartilage damage
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A comparison of aerosol chemical and optical properties from the 1st and 2nd Aerosol Characterization Experiments
Shipboard measurements of aerosol chemical composition and optical properties were made during both ACE-1 and ACE-2. ACE-1 focused on remote marine aerosol minimally perturbed by continental sources. ACE-2 studied the outflow of European aerosol into the NE Atlantic atmosphere. A variety of air masses were sampled during ACE-2 including Atlantic, polar, Iberian Peninsula, Mediterranean, and Western European. Reported here are mass size distributions of non-sea salt (nss) sulfate, sea salt, and methanesulfonate and submicron and supermicron concentrations of black and organic carbon. Optical parameters include submicron and supermicron aerosol scattering and backscattering coefficients at 550 nm, the absorption coefficient at 550±20 nm, the Ă
ngström exponent for the 550 and 700 nm wavelength pair, and single scattering albedo at 550 nm. All data are reported at the measurement relative humidity of 55%. Measured concentrations of nss sulfate aerosol indicate that, relative to ACE-1, ACE-2 aerosol during both marine and continental flow was impacted by continental sources. Thus, while sea salt controlled the aerosol chemical composition and optical properties of both the submicron and supermicron aerosol during ACE-1, it played a relatively smaller role in ACE-2. This is confirmed by the larger average Ă
ngström exponent for ACE-2 continental aerosol of 1.2±0.26 compared to the ACE-1 average of -0.03±0.38. The depletion of chloride from sea salt aerosol in ACE-2 continental air masses averaged 55±25% over all particle sizes. This compares to the ACE-2 marine average of 4.8±18% and indicates the enhanced interaction of anthropogenic acids with sea salt as continental air masses are transported into the marine atmosphere. Single scattering albedos averaged 0.95±0.03 for ACE-2 continental air masses. Averages for ACE-2 and ACE-1 marine air masses were 0.98±0.01 and 0.99±0.01, respectively
A metaâanalysis of the effect of visiting zoos and aquariums on visitorsâ conservation knowledge, beliefs, and behavior
Zoos and aquariums are well placed to connect visitors with the issues facing biodiversity globally and many deliver interventions that seek to influence visitorsâ beliefs and behaviors with respect to conservation. However, despite primary studies evaluating the effect of such interventions, the overall effect of engaging with zoos and the factors that influence this effect remain unclear. We conducted a systematic review to investigate the effect of zooâled interventions on knowledge, beliefs (attitudes, intentions, selfâefficacy, and social norms), and behavior among zoo visitors. These outcomes were identified using the Theory of Planned Behavior as a theoretical lens. We identified and described the nature of zooâled interventions in 56 studies and used the behavior change technique (BCT) taxonomy to identify 6 specific BCTs used in interventions to date. Multilevel metaâanalyses revealed a small to medium positive effect of engaging with zooâled interventions on outcomes (d+ = 0.40, 95% confidence interval = 0.28â0.51). Specifically, visitors were more knowledgeable about conservation issues, held more favorable attitudes toward conservation, and reported being more likely to act for the benefit of biodiversity. No evidence of publication bias was present. Effect sizes were, however, heterogeneous and subgroup analyses revealed that the nature of the intervention or type of outcome did not explain this variance. Larger effects were, however, found in studies conducted at a single institution relative to research at multiple institutions and studies that used withinâparticipant designs relative to betweenâparticipant designs. Taken together, these findings demonstrate how behavior change frameworks can be used to describe zooâled interventions and supports the assertion that zoos and aquariums can promote changes in beliefs and behaviors that may help protect biodiversity
Cassini VIMS observations of H3+ emission on the nightside of Jupiter
We present the first detailed analysis of H3+ nightside emission from Jupiter, using Visual and Infrared Mapping Spectrometer (VIMS) data from the Cassini flyby in 2000â2001, producing the first Jovian maps of nightside H3+ emission, temperature, and column density. Using these, we identify and characterize regions of H3+ nightside emission, compared against past observations of H3+ emission on the dayside. We focus our investigation on the region previously described as âmid-to-low latitude emission,â the source for which has been controversial. We find that the brightest of this emission is generated at Jovigraphic latitudes similar to the most equatorward extent of the main auroral emission but concentrated at longitudes eastward of this emission. The emission is produced by enhanced H3+ density, with temperatures dropping away in this region. This emission has a loose association with the predicted location of diffuse aurora produced by pitch angle scattering in the north, but not in the south. This emission also lays in the path of subrotating winds flowing from the aurora, suggesting a transport origin. Some differences are seen between dayside and nightside subauroral emissions, with dayside emission extending more equatorward, perhaps caused by the lack of sunlight ionization on the nightside, and unmeasured changes in temperature. Ionospheric temperatures are hotter in the polar region (~1100â1500âK), dropping away toward the equator (as low as 750âK), broadly similar to values on the dayside, highlighting the dominance of auroral effects in the polar region. No equatorial emission is observed, suggesting that very little particle precipitation occurs away from the polar regions
Methods for detecting PER2::LUCIFERASE bioluminescence rhythms in freely moving mice [preprint]
Circadian rhythms are driven by daily oscillations of gene expression. An important tool for studying cellular and tissue rhythms is the use of a gene reporter, such as bioluminescence from the reporter gene luciferase controlled by a rhythmically expressed gene of interest. Here we describe methods that allow measurement of bioluminescence from a freely-moving mouse housed in a standard cage. Using a LumiCycle In Vivo (Actimetrics), we determined conditions that allow detection of circadian rhythms of bioluminescence from the PER2 reporter, PER2::LUC, in freely behaving mice. We tested delivery of D-luciferin via a subcutaneous minipump and in the drinking water. Further, we demonstrate that a synthetic luciferase substrate, CycLuc1, can support circadian rhythms of bioluminescence, even when delivered at a lower concentration than D-luciferin. We share our analysis scripts and suggestions for further improvements in this method. This approach will be straightforward to apply to mice with tissue-specific reporters, allowing insights into responses of specific peripheral clocks to perturbations such as environmental or pharmacological manipulations
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