6,459 research outputs found
The paradox of power: understanding fiscal capacity in Imperial China and absolutist regimes
Tax extraction in Qing China was low relative to Western Europe. It is not obvious why: China was much more absolutist and had stronger rights over property and people. Why did the Chinese not convert their absolute power into revenue? We propose a model, supported by historical evidence, which suggests that i) the center could not ask its tax collecting agents to levy high taxes because it would incentivize agents to overtax the peasantry; ii) the center could not pay agents high wages in return for high taxes because the center had no mechanism to commit to refrain from confiscating the agentâs resources in times of crisis. A solution to this problem was to offer agents a low wage and ask for low taxes while allowing agents to take extra, unmonitored taxes from the peasantry. This solution only worked because of Chinaâs weak administrative capacity due its size and poor monitoring technology. This analysis suggests that low investment in administrative capacity can be an optimal solution for an absolutist ruler since it substitutes for a credible commitment to refrain from confiscation. Our study carries implications for state capacity beyond Imperial China
Edscottite, Fe_5C_2, a New Iron Carbide Mineral from the Wedderburn Iron Meteorite
The Wedderburn iron meteorite, found as a single 210-g mass in Victoria, Australia in 1951, is a
Ni-rich ataxite belonging to subgroup sLH of the IAB complex (Low-Au, High-Ni subgroup). It is one of the most
Ni-rich irons known (23.4 wt.% Ni [1]), initially classified as group IIID. During a re-investigation of a polished thick
section of Wedderburn, we identified a new iron-carbide mineral, Fe5C2 with the C2/c Pd5B2-type structure, named
âedscottiteâ (Fig. 1). Field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron
back-scatter diffraction (EBSD) and electron probe microanalysis (EPMA) were used to characterize edscottite and
associated phases. This mineral was first identified in Wedderburn [2,3]; synthetic Fe_5C_2 was previously known (e.g.,
[4-6]). We report here the first natural occurrence of Fe_5C_2 in an iron meteorite as a new carbide mineral. Edscottite
(IMA 2018-086a) was approved by the IMA-CNMNC [7]. The mineral name is in honor of Edward (Ed) R. D. Scott,
University of Hawaiâi, USA, for his seminal contributions to meteorite research. He discovered haxonite, (Fe,Ni)_(23)C_6
[8] as well as this new iron carbide [2,3]
Ideology and Economic Change
This paper revisits the old theses of the contrasting paths to modernization between Japan and China. It develops a new analytical framework regarding the role of ideology and ideological changeâMeiji Japanâs decisive turn towards the West pitted against Qing Chinaâs lethargic response to Western imperialismâas the key driver behind these contrasting paths. Our framework and historical narrative highlight the contrast between Tokugawa Japanâs feudal, decentralized political regime and Qing Chinaâs centralized bureaucratic system as a key determinant driving the differential patterns of ideological realignment. We argue that the 1894-95 Japanese naval victory over China could not be justified under the prevailing Imperial Chinese ideology and thus served as the catalyst for Chinaâs subsequent ideological transformation, which occurred via borrowing Japanâs successful Meiji reforms of both institutions and ideology. Our analytical framework, developed from a comparative historical narrative, sheds new insights on the importance of ideology and ideological change for our understanding of political and economic change
Application of Bayesian graphs to SN Ia data analysis and compression
Bayesian graphical models are an efficient tool for modelling complex data
and derive self-consistent expressions of the posterior distribution of model
parameters. We apply Bayesian graphs to perform statistical analyses of Type Ia
supernova (SN Ia) luminosity distance measurements from the joint light-curve
analysis (JLA) data set. In contrast to the approach used in previous
studies, the Bayesian inference allows us to fully account for the
standard-candle parameter dependence of the data covariance matrix. Comparing
with analysis results, we find a systematic offset of the marginal
model parameter bounds. We demonstrate that the bias is statistically
significant in the case of the SN Ia standardization parameters with a maximal
6 shift of the SN light-curve colour correction. In addition, we find
that the evidence for a host galaxy correction is now only 2.4 .
Systematic offsets on the cosmological parameters remain small, but may
increase by combining constraints from complementary cosmological probes. The
bias of the analysis is due to neglecting the parameter-dependent
log-determinant of the data covariance, which gives more statistical weight to
larger values of the standardization parameters. We find a similar effect on
compressed distance modulus data. To this end, we implement a fully consistent
compression method of the JLA data set that uses a Gaussian approximation of
the posterior distribution for fast generation of compressed data. Overall, the
results of our analysis emphasize the need for a fully consistent Bayesian
statistical approach in the analysis of future large SN Ia data sets.Comment: 14 pages, 13 figures, 5 tables. Submitted to MNRAS. Compression
utility available at https://gitlab.com/congma/libsncompress/ and example
cosmology code with machine-readable version of Tables A1 & A2 at
https://gitlab.com/congma/sn-bayesian-model-example/ v2: corrected typo in
author's name. v3: 15 pages, incl. corrections, matches the accepted versio
The Nature and Frequency of Outflows from Stars in the Central Orion Nebula Cluster
Recent Hubble Space Telescope images have allowed the determination with
unprecedented accuracy of motions and changes of shocks within the inner Orion
Nebula. These originate from collimated outflows from very young stars, some
within the ionized portion of the nebula and others within the host molecular
cloud. We have doubled the number of Herbig-Haro objects known within the inner
Orion Nebula. We find that the best-known Herbig-Haro shocks originate from a
relatively few stars, with the optically visible X-ray source COUP 666 driving
many of them.
While some isolated shocks are driven by single collimated outflows, many
groups of shocks are the result of a single stellar source having jets oriented
in multiple directions at similar times. This explains the feature that shocks
aligned in opposite directions in the plane of the sky are usually blue shifted
because the redshifted outflows pass into the optically thick Photon Dominated
Region behind the nebula. There are two regions from which optical outflows
originate for which there are no candidate sources in the SIMBAD data base.Comment: 152 pages, 46 figures, 7 tables. Accepted by A
Medical Image Retrieval: Past and Present
With the widespread dissemination of picture archiving and communication systems (PACSs) in hospitals, the amount of imaging data is rapidly increasing. Effective image retrieval systems are required to manage these complex and large image databases. The authors reviewed the past development and the present state of medical image retrieval systems including text-based and content-based systems. In order to provide a more effective image retrieval service, the intelligent content-based retrieval systems combined with semantic systems are required
A bi-dimensional finite mixture model for longitudinal data subject to dropout
In longitudinal studies, subjects may be lost to follow-up, or miss some of
the planned visits, leading to incomplete response sequences. When the
probability of non-response, conditional on the available covariates and the
observed responses, still depends on unobserved outcomes, the dropout mechanism
is said to be non ignorable. A common objective is to build a reliable
association structure to account for dependence between the longitudinal and
the dropout processes. Starting from the existing literature, we introduce a
random coefficient based dropout model where the association between outcomes
is modeled through discrete latent effects. These effects are outcome-specific
and account for heterogeneity in the univariate profiles. Dependence between
profiles is introduced by using a bi-dimensional representation for the
corresponding distribution. In this way, we define a flexible latent class
structure which allows to efficiently describe both dependence within the two
margins of interest and dependence between them. By using this representation
we show that, unlike standard (unidimensional) finite mixture models, the non
ignorable dropout model properly nests its ignorable counterpart. We detail the
proposed modeling approach by analyzing data from a longitudinal study on the
dynamics of cognitive functioning in the elderly. Further, the effects of
assumptions about non ignorability of the dropout process on model parameter
estimates are (locally) investigated using the index of (local) sensitivity to
non-ignorability
Pediatric endocrine society survey of diabetes practices in the United States: What is the current state?
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144633/1/pedi12677.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144633/2/pedi12677_am.pd
A model for removing the increased recall of recent events from the temporal distribution of autobiographical memory
The reminiscence bump is the tendency to recall relatively many personal events from the period in which the individual was between 10 and 30Â years old. This effect has only been found in autobiographical memory studies that used participants who were older than 40Â years of age. The increased recall of recent events possibly obscures the reminiscence bump in the results of younger participants. In this study, a model was proposed that removes the increase for recent events from the temporal distribution. The model basically estimates a retention function based on the 10 most recent years from the observed distributions and divides the observed distributions by predictions derived from the estimated retention function. The model was examined with three simulated data sets and one experimental data set. The results of the experiment offered two practical examples of how the model could be used to investigate the temporal distribution of autobiographical memories
Small Oscillatory Accelerations, Independent of Matrix Deformations, Increase Osteoblast Activity and Enhance Bone Morphology
A range of tissues have the capacity to adapt to mechanical challenges, an attribute presumed to be regulated through deformation of the cell and/or surrounding matrix. In contrast, it is shown here that extremely small oscillatory accelerations, applied as unconstrained motion and inducing negligible deformation, serve as an anabolic stimulus to osteoblasts in vivo. Habitual background loading was removed from the tibiae of 18 female adult mice by hindlimb-unloading. For 20 min/d, 5 d/wk, the left tibia of each mouse was subjected to oscillatory 0.6 g accelerations at 45 Hz while the right tibia served as control. Sham-loaded (nâ=â9) and normal age-matched control (nâ=â18) mice provided additional comparisons. Oscillatory accelerations, applied in the absence of weight bearing, resulted in 70% greater bone formation rates in the trabeculae of the metaphysis, but similar levels of bone resorption, when compared to contralateral controls. Quantity and quality of trabecular bone also improved as a result of the acceleration stimulus, as evidenced by a significantly greater bone volume fraction (17%) and connectivity density (33%), and significantly smaller trabecular spacing (â6%) and structural model index (â11%). These in vivo data indicate that mechanosensory elements of resident bone cell populations can perceive and respond to acceleratory signals, and point to an efficient means of introducing intense physical signals into a biologic system without putting the matrix at risk of overloading. In retrospect, acceleration, as opposed to direct mechanical distortion, represents a more generic and safe, and perhaps more fundamental means of transducing physical challenges to the cells and tissues of an organism
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