1,044 research outputs found
Comparative Colonialism : Russia in the North Pacific and Central Asia
This article is a comparative analysis of Russian colonialism in the North Pacific and in Central Asia. The Russian Empire exhibited a similar overall approach to the colonization of both regions during the eighteenth and nineteenth centuries. This paper compares the interests in both regions, the means of colonization, and the outcomes of these processes. Attention is paid in the article to the important roles which overland and sea exploration, settler colonialism, and other factors had in the process. Although the overall approach to colonization was similar, the outcomes of these processes led to quite distinct results. This research has been facilitated through a Japan Society for the Promotion of Science (JSPS) Kaken grant, 18K00919
Russian Early Geographic Exploration and Encounters in the North Pacific
This article examines the earliest Russian geographic and nautical exploration of the North Pacific and Japan’s Northern Territories and their importance within the context of global history, and also in comparison to similar research which Russians conducted in Central Asia. The author identifies some historically significant explorative expeditions and travelers from the Russian Empire to the region, and includes descriptions of their initial findings. It is argued that Russian early efforts to explore the area were somewhat haphazard and did not follow a clearly-orchestrated pattern or objective, which made explorations both infrequent and somewhat sporadic. There is also discussions of some of the outcomes of these explorations, which included cross-cultural encounters with both Japanese people and other peoples of the North Pacific, including the Kamchadals and the Ainu
The interactions between municipal socioeconomic status and age on hip fracture risk
The final publication is available at Springer via http://dx.doi.org/10.1007/s00198-014-2869-0SUMMARY: Age modifies the effect of area-level socioeconomic status (SES) in the risk of fragility hip fractures (HF). For older individuals, the risk of HF increases as SES increases. For younger individuals, risk of HF increases as SES decreases. Our study may help decision-makers to better direct the implementation of political decisions. INTRODUCTION: The effect of socioeconomic status (SES) on hip fracture (HF) incidence remains unclear. The objective of this study is to evaluate the association between HF incidence and municipality-level SES as well as interactions between age and SES. METHODS: From the Portuguese Hospital Discharge Database, we selected hospitalizations (2000-2010) of patients aged 50+, with HF diagnosis (codes 820.x, ICD9-CM), caused by traumas of low/moderate energy, excluding bone cancer cases and readmissions for aftercare. Municipalities were classified according to SES (deprived to affluent) using 2001 Census data. A spatial Bayesian hierarchical regression model (controlling for data heterogeneity and spatial autocorrelation), using the Poisson distribution, was used to quantify the relative risk (RR) of HF, 95% credible interval (95%CrI), and analyze the interaction between age and SES after adjusting for rural conditions. RESULTS: There were 96,905 HF, 77.3% of which were on women who, on average, were older than men (mean age 81.2±8.5 vs 78.2±10.1 years) at admission (p<0.001). In women, there was a lower risk associated with better SES: RR=0.83 (95%CrI 0.65-1.00) for affluent versus deprived. There was an inverse association between SES and HF incidence rate in the youngest and a direct association in the oldest, for both sexes, but significant only between deprived and affluent in older ages (≥75 years). CONCLUSIONS: Interaction between SES and age may be due to inequalities in lifestyles, access to health systems, and preventive actions. These results may help decision-makers to better understand the epidemiology of hip fractures and to better direct the available funding.Programa Operacional Factores de Competitividade (COMPETE)Fundação para a Ciência e a Tecnologia (FCT
Scalp Hematoma Characteristics Associated with Intracranial Injury in Pediatric Minor Head Injury
Objectives Minor head trauma accounts for a significant proportion of pediatric emergency department (ED) visits. In children younger than 24 months, scalp hematomas are thought to be associated with the presence of intracranial injury (ICI). We investigated which scalp hematoma characteristics were associated with increased odds of ICI in children less than 17 years who presented to the ED following minor head injury and whether an underlying linear skull fracture may explain this relationship. Methods This was a secondary analysis of 3,866 patients enrolled in the Canadian Assessment of Tomography of Childhood Head Injury (CATCH) study. Information about scalp hematoma presence (yes/no), location (frontal, temporal/parietal, occipital), and size (small and localized, large and boggy) was collected by emergency physicians using a structured data collection form. ICI was defined as the presence of an acute brain lesion on computed tomography. Logistic regression analyses were adjusted for age, sex, dangerous injury mechanism, irritability on examination, suspected open or depressed skull fracture, and clinical signs of basal skull fracture. Results ICI was present in 159 (4.1%) patients. The presence of a scalp hematoma (n = 1,189) in any location was associated with significantly greater odds of ICI (odds ratio [OR] = 4.4, 95% confidence interval [CI] = 3.06 to 6.02), particularly for those located in temporal/parietal (OR = 6.0, 95% CI = 3.9 to 9.3) and occipital regions (OR = 5.6, 95% CI = 3.5 to 8.9). Both small and localized and large and boggy hematomas were significantly associated with ICI, although larger hematomas conferred larger odds (OR = 9.9, 95% CI = 6.3 to 15.5). Although the presence of a scalp hematoma was associated with greater odds of ICI in all age groups, odds were greatest in children aged 0 to 6 months (OR = 13.5, 95% CI = 1.5 to 119.3). Linear skull fractures were present in 156 (4.0%) patients. Of the 111 patients with scalp hematoma and ICI, 57 (51%) patients had a linear skull fracture and 54 (49%) did not. The association between scalp hematoma and ICI attenuated but remained significant after excluding patients with linear skull fracture (OR = 3.3, 95% CI = 2.1 to 5.1). Conclusions Large and boggy and nonfrontal scalp hematomas had the strongest association with the presence of ICI in this large pediatric cohort. Although children 0 to 6 months of age were at highest odds, the presence of a scalp hematoma also independently increased the odds of ICI in older children and adolescents. The presence of a linear skull fracture only partially explained this relation, indicating that ruling out a skull fracture beneath a hematoma does not obviate the risk of intracranial pathology
Resonant Absorption as Mode Conversion?
Resonant absorption and mode conversion are both extensively studied
mechanisms for wave "absorption" in solar magnetohydrodynamics (MHD). But are
they really distinct? We re-examine a well-known simple resonant absorption
model in a cold MHD plasma that places the resonance inside an evanescent
region. The normal mode solutions display the standard singular resonant
features. However, these same normal modes may be used to construct a ray
bundle which very clearly undergoes mode conversion to an Alfv\'en wave with no
singularities. We therefore conclude that resonant absorption and mode
conversion are in fact the same thing, at least for this model problem. The
prime distinguishing characteristic that determines which of the two
descriptions is most natural in a given circumstance is whether the converted
wave can provide a net escape of energy from the conversion/absorption region
of physical space. If it cannot, it is forced to run away in wavenumber space
instead, thereby generating the arbitrarily small scales in situ that we
recognize as fundamental to resonant absorption and phase mixing. On the other
hand, if the converted wave takes net energy way, singularities do not develop,
though phase mixing may still develop with distance as the wave recedes.Comment: 23 pages, 8 figures, 2 tables; accepted by Solar Phys (July 9 2010
Rotating Resonator-Oscillator Experiments to Test Lorentz Invariance in Electrodynamics
In this work we outline the two most commonly used test theories (RMS and
SME) for testing Local Lorentz Invariance (LLI) of the photon. Then we develop
the general framework of applying these test theories to resonator experiments
with an emphasis on rotating experiments in the laboratory. We compare the
inherent sensitivity factors of common experiments and propose some new
configurations. Finally we apply the test theories to the rotating cryogenic
experiment at the University of Western Australia, which recently set new
limits in both the RMS and SME frameworks [hep-ph/0506074].Comment: Submitted to Lecture Notes in Physics, 36 pages, minor modifications,
updated list of reference
Local mean-field study of capillary condensation in silica aerogels
We apply local mean-field (i.e. density functional) theory to a lattice model
of a fluid in contact with a dilute, disordered gel network. The gel structure
is described by a diffusion-limited cluster aggregation model. We focus on the
influence of porosity on both the hysteretic and the equilibrium behavior of
the fluid as one varies the chemical potential at low temperature. We show that
the shape of the hysteresis loop changes from smooth to rectangular as the
porosity increases and that this change is associated to disorder-induced
out-of-equilibrium phase transitions that differ on adsorption and on
desorption. Our results provide insight in the behavior of He in silica
aerogels.Comment: 19 figure
Atmospheres from very low-mass stars to extrasolar planets
Within the next few years, several instruments aiming at imaging extrasolar
planets will see first light. In parallel, low mass planets are being searched
around red dwarfs which offer more favorable conditions, both for radial
velocity detection and transit studies, than solar-type stars. We review recent
advancements in modeling the stellar to substellar transition. The revised
solar oxygen abundances and cloud models allow to reproduce the photometric and
spectroscopic properties of this transition to a degree never achieved before,
but problems remain in the important M-L transition characteristic of the
effective temperature range of characterizable exoplanets.Comment: submitted to Memorie della Societa Astronomica Italian
Macroscopic limits and phase transition in a system of self-propelled particles
We investigate systems of self-propelled particles with alignment
interaction. Compared to previous work, the force acting on the particles is
not normalized and this modification gives rise to phase transitions from
disordered states at low density to aligned states at high densities. This
model is the space inhomogeneous extension of a previous work by Frouvelle and
Liu in which the existence and stability of the equilibrium states were
investigated. When the density is lower than a threshold value, the dynamics is
described by a non-linear diffusion equation. By contrast, when the density is
larger than this threshold value, the dynamics is described by a hydrodynamic
model for self-alignment interactions previously derived in Degond and Motsch.
However, the modified normalization of the force gives rise to different
convection speeds and the resulting model may lose its hyperbolicity in some
regions of the state space
Mindfulness meditators show altered distributions of early and late neural activity markers of attention in a response inhibition task
Attention is vital for optimal behavioural performance in every-day life. Mindfulness meditation has been shown to enhance attention. However, the components of attention altered by meditation and the related neural activities are underexplored. In particular, the contributions of inhibitory processes and sustained attention are not well understood. To address these points, 34 meditators were compared to 28 age and gender matched controls during electroencephalography (EEG) recordings of neural activity during a Go/Nogo response inhibition task. This task generates a P3 event related potential, which is related to response inhibition processes in Nogo trials, and attention processes across both trial types. Compared with controls, meditators were more accurate at responding to Go and Nogo trials. Meditators showed a more frontally distributed P3 to both Go and Nogo trials, suggesting more frontal involvement in sustained attention rather than activity specific to response inhibition. Unexpectedly, meditators also showed increased positivity over the right parietal cortex prior to visual information reaching the occipital cortex (during the pre-C1 window). Both results were positively related to increased accuracy across both groups. The results suggest that meditators show altered engagement of neural regions related to attention, including both higher order processes generated by frontal regions, and sensory anticipation processes generated by poster regions. This activity may reflect an increased capacity to modulate a range of neural processes in order to meet task requirements. This increased capacity may underlie the improved attentional function observed in mindfulness meditators.Neil W. Bailey, Gabrielle Freedman, Kavya Raj, Caley M. Sullivan, Nigel C. Rogasch, Sung W. Chung, Kate E. Hoy, Richard Chambers, Craig Hassed, Nicholas T. Van Dam, Thomas Koenig, Paul B. Fitzgeral
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