764 research outputs found

    A DECOMPOSED REGRESSION MODEL FOR MEASURING STRUCTURAL CHANGES IN THE FLOUR MILLING INDUSTRY

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    This paper presents a decomposed Poisson regression model based on count data that evaluates the size distribution, the changing number of flour mills for each size class, and the concentration of market power, simultaneously. This model also allows us to test dominant price leadership model.Agribusiness, Industrial Organization,

    A Note on the Reliability Tests of Estimates from ARMS Data

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    USDA uses the concept of "publish-ability" rather than statistical reliability of an estimate for quality validation of USDA estimates, which is solely based on the sample size and the coefficient of variation (CV). We demonstrate conceptually how the reliability of the sample mean can be tested by estimating the upper and lower bounds of the confidence interval for an unknown population mean using the CV. However, the reliability test for the sample mean can be made only under the normality assumption. USDA multiple-way Agricultural Resource Management Survey (ARMS) estimates are used to illustrate the relative measure of precision for sample-based estimators.Research Methods/ Statistical Methods,

    Chinese social media reaction to the MERS-CoV and avian influenza A(H7N9) outbreaks

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    BACKGROUND: As internet and social media use have skyrocketed, epidemiologists have begun to use online data such as Google query data and Twitter trends to track the activity levels of influenza and other infectious diseases. In China, Weibo is an extremely popular microblogging site that is equivalent to Twitter. Capitalizing on the wealth of public opinion data contained in posts on Weibo, this study used Weibo as a measure of the Chinese people's reactions to two different outbreaks: the 2012 Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreak, and the 2013 outbreak of human infection of avian influenza A(H7N9) in China. METHODS: Keyword searches were performed in Weibo data collected by The University of Hong Kong's Weiboscope project. Baseline values were determined for each keyword and reaction values per million posts in the days after outbreak information was released to the public. RESULTS: The results show that the Chinese people reacted significantly to both outbreaks online, where their social media reaction was two orders of magnitude stronger to the H7N9 influenza outbreak that happened in China than the MERS-CoV outbreak that was far away from China. CONCLUSIONS: These results demonstrate that social media could be a useful measure of public awareness and reaction to disease outbreak information released by health authorities.published_or_final_versio

    Perinatal stabilisation of infants born with congenital diaphragmatic hernia: A review of current concepts

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    Congenital diaphragmatic hernia (CDH) is associated with high mortality rates and significant pulmonary morbidity, mainly due to disrupted lung development related to herniation of abdominal organs into the chest. Pulmonary hypertension is a major contributor to both mortality and morbidity, however, treatment modalities are limited. Novel prenatal and postnatal interventions, such as fetal surgery and medical treatments, are currently under investigation. Until now, the perinatal stabilisation period immediately after birth has been relatively overlooked, although optimising support in these early stages may be vital in improving outcomes. Moreover, physiological parameters obtained from the perinatal stabilisation period could serve as early predictors of adverse outcomes, thereby facilitating both prevention and early treatment of these conditions. In this review, we focus on the perinatal stabilisation period by discussing the current delivery room guidelines in infants born with CDH, th

    Multimodal X-ray imaging of nanocontainer-treated macrophages and calcium distribution in the perilacunar bone matrix

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    Studies of biological systems typically require the application of several complementary methods able to yield statistically-relevant results at a unique level of sensitivity. Combined X-ray fluorescence and ptychography offer excellent elemental and structural imaging contrasts at the nanoscale. They enable a robust correlation of elemental distributions with respect to the cellular morphology. Here we extend the applicability of the two modalities to higher X-ray excitation energies, permitting iron mapping. Using a long-range scanning setup, we applied the method to two vital biomedical cases. We quantified the iron distributions in a population of macrophages treated with Mycobacterium-tuberculosis-targeting iron-oxide nanocontainers. Our work allowed to visualize the internalization of the nanocontainer agglomerates in the cytosol. From the iron areal mass maps, we obtained a distribution of antibiotic load per agglomerate and an average areal concentration of nanocontainers in the agglomerates. In the second application we mapped the calcium content in a human bone matrix in close proximity to osteocyte lacunae (perilacunar matrix). A concurrently acquired ptychographic image was used to remove the mass-thickness effect from the raw calcium map. The resulting ptychography-enhanced calcium distribution allowed then to observe a locally lower degree of mineralization of the perilacunar matrix

    A pace and shape perspective on fertility

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    Ageing is ubiquitous to all organisms, but ageing does not always mean senescence. Counter to most evolutionary theories of ageing, the patterns of mortality and reproduction may remain unchanged or improve with age, as well as deteriorate. Describing this diversity presents a challenge to eco‐evolutionary demography. The pace–shape framework of mortality tackled this challenge to qualify and quantify orthogonal components of ageing patterns in mortality. Here, we extend this framework to fertility. Analogous to the logic of the mortality framework, we define a perspective, a framework and novel methods for the pace and shape of fertility. These distinguish between orthogonal components of time‐scale (pace) and distribution (shape) of reproduction over adult life span. Our pace and shape framework mirrors that of mortality, through a shift of perspective from the mother giving birth, to the offspring being born. Our new measures overcome many problems associated with measuring natural fertility trajectories, have both a clear biological and mathematical interpretation, can be intuitively visualized and satisfy and extend important conditions of the pace–shape paradigm. A comprehensive framework of fertility pace–shape facilitates ecological and evolutionary research addressing interactions and trade‐offs between components of birth and death patterns, across the whole tree of life. The burgeoning emergence of large comparative demographic data sources across wide environmental, geographical, temporal and phylogenetic ranges, combined with pace–shape measures, opens the door to comparative analyses of ageing which were never possible before

    Aging impairs the osteocytic regulation of collagen integrity and bone quality

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    Poor bone quality is a major factor in skeletal fragility in elderly individuals. The molecular mechanisms that establish and maintain bone quality, independent of bone mass, are unknown but are thought to be primarily determined by osteocytes. We hypothesize that the age-related decline in bone quality results from the suppression of osteocyte perilacunar/canalicular remodeling (PLR), which maintains bone material properties. We examined bones from young and aged mice with osteocyte-intrinsic repression of TGFβ signaling (TβRI

    Physiological-based cord clamping versus immediate cord clamping for infants born with a congenital diaphragmatic hernia (PinC):study protocol for a multicentre, randomised controlled trial

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    Introduction Pulmonary hypertension is a majordeterminant of postnatal survival in infants with acongenital diaphragmatic hernia (CDH). The current careduring the perinatal stabilisation period in these infantsmight contribute to the development of pulmonaryhypertension after birth—in particular umbilical cordclamping before lung aeration. An ovine model ofdiaphragmatic hernia demonstrated that cord clampingafter lung aeration, called physiological-based cordclamping (PBCC), avoided the initial high pressures in thelung vasculature while maintaining adequate blood flow,thereby avoiding vascular remodelling and aggravationof pulmonary hypertension. We aim to investigate if theimplementation of PBCC in the perinatal stabilisation periodof infants born with a CDH could reduce the incidence ofpulmonary hypertension in the first 24 hours after birth.Methods and analysis We will perform a multicentre,randomised controlled trial in infants with an isolatedleft-sided CDH, born at ≥35.0 weeks. Before birth, infantswill be randomised to either PBCC or immediate cordclamping, stratified by treatment centre and severity ofpulmonary hypoplasia on antenatal ultrasound. PBCCwill be performed using a purpose- built resuscitationtrolley. Cord clamping will be performed when the infantis considered respiratory stable, defined as a heartrate >100 bpm, preductal oxygen saturation >85%,while using a fraction of inspired oxygen of <0.5. Theprimary outcome is pulmonary hypertension diagnosedin the first 24 hours after birth, based on clinical andechocardiographic parameters. Secondary outcomesinclude neonatal as well as maternal outcomes.Ethics and dissemination Central ethical approvalwas obtained from the Medical Ethical Committee ofthe Erasmus MC, Rotterdam, The Netherlands (METC2019-0414). Local ethical approval will be obtained bysubmitting the protocol to the regulatory bodies and localinstitutional review boards
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