Enhancing weak transient signals in SEVIRI false color imagery: application to dust source detection in southern Africa

A method is described to significantly enhance the signature of dust events using observations from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI). The approach involves the derivation of a composite clear-sky signal for selected channels on an individual time step and pixel basis. These composite signals are subtracted from each observation in the relevant channels to enhance weak transient signals associated with either (a) low levels of dust emission or (b) dust emissions with high salt or low quartz content. Different channel combinations, of the differenced data from the steps above, are then rendered in false color imagery for the purpose of improved identification of dust source locations and activity. We have applied this clear-sky difference (CSD) algorithm over three (globally significant) source regions in southern Africa: the Makgadikgadi Basin, Etosha Pan, and the Namibian and western South African coast. Case study analyses indicate three notable advantages associated with the CSD approach over established image rendering methods: (i) an improved ability to detect dust plumes, (ii) the observation of source activation earlier in the diurnal cycle, and (iii) an improved ability to resolve and pinpoint dust plume source locations

Defining and Analysing Resource Assignments in Business Processes with RAL

Business process (BP) modelling notations tend to stray their attention from (human) resource management, unlike other aspects such as control flow or even data flow. They not only offer little intuitive languages to assign resources to BP activities, but neither link BPs with the structure of the organization where they are used, so BP models can easily contain errors such as the assignment of resources that do not belong to the organizational model. In this paper we address this problem and define RAL (Resource Assignment Language), a domainspecific language explicitly developed to assign resources to the activities of a BP model. RAL makes BPs aware of organizational structures. Besides, RAL semantics is based on an OWL-DL ontology, which enables the automatic analysis of resource assignment expressions, thus allowing the extraction of information from the resource assignments, and the detection of inconsistencies and assignment conflicts

Epidemiologic Study of Dental Caries Experience and Between-Meal Eating Patterns

The relationship between dental caries and between-meal snacks was investigated in a study of 1,486 high school students. The participants completed a questionnaire on between-meal habits and then were given dental examinations. The lack of differences in dental caries between racial and geographic groups was not related to the frequency of sucrose-containing, between-meal snacks.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66591/2/10.1177_00220345730520022501.pd

Galactic X-ray binary jets

With their relatively fast variability time-scales, Galactic X-ray binaries provide an excellent laboratory to explore the physics of accretion and related phenomena, most notably outflows, over different regimes. After comparing the phenomenology of jets in black hole X-ray binary systems to that of neutron stars, here I discuss the role of the jet at very low Eddington ratios, and present preliminary results obtained by fitting the broadband spectral energy distribution of a quiescent black hole binary with a `maximally jet-dominated' model.Comment: Refereed version, accepted for publication in Astrophysics & Space Scienc

Endocrine disruptor compounds-a cause of impaired immune tolerance driving inflammatory disorders of pregnancy?

Endocrine disrupting compounds (EDCs) are prevalent and ubiquitous in our environment and have substantial potential to compromise human and animal health. Amongst the chronic health conditions associated with EDC exposure, dysregulation of reproductive function in both females and males is prominent. Human epidemiological studies demonstrate links between EDC exposure and infertility, as well as gestational disorders including miscarriage, fetal growth restriction, preeclampsia, and preterm birth. Animal experiments show EDCs administered during gestation, or to either parent prior to conception, can interfere with gamete quality, embryo implantation, and placental and fetal development, with consequences for offspring viability and health. It has been presumed that EDCs operate principally through disrupting hormone-regulated events in reproduction and fetal development, but EDC effects on maternal immune receptivity to pregnancy are also implicated. EDCs can modulate both the innate and adaptive arms of the immune system, to alter inflammatory responses, and interfere with generation of regulatory T (Treg) cells that are critical for pregnancy tolerance. Effects of EDCs on immune cells are complex and likely exerted by both steroid hormone-dependent and hormone-independent pathways. Thus, to better understand how EDCs impact reproduction and pregnancy, it is imperative to consider how immune-mediated mechanisms are affected by EDCs. This review will describe evidence that several EDCs modify elements of the immune response relevant to pregnancy, and will discuss the potential for EDCs to disrupt immune tolerance required for robust placentation and optimal fetal development.John E. Schjenken, Ella S. Green, Tenuis S. Overduin, Chui Yan Mah, Darryl L. Russell and Sarah A. Robertso

The balance of power: accretion and feedback in stellar mass black holes

In this review we discuss the population of stellar-mass black holes in our galaxy and beyond, which are the extreme endpoints of massive star evolution. In particular we focus on how we can attempt to balance the available accretion energy with feedback to the environment via radiation, jets and winds, considering also possible contributions to the energy balance from black hole spin and advection. We review quantitatively the methods which are used to estimate these quantities, regardless of the details of the astrophysics close to the black hole. Once these methods have been outlined, we work through an outburst of a black hole X-ray binary system, estimating the flow of mass and energy through the different accretion rates and states. While we focus on feedback from stellar mass black holes in X-ray binary systems, we also consider the applicability of what we have learned to supermassive black holes in active galactic nuclei. As an important control sample we also review the coupling between accretion and feedback in neutron stars, and show that it is very similar to that observed in black holes, which strongly constrains how much of the astrophysics of feedback can be unique to black holes.Comment: To be published in Haardt et al. Astrophysical Black Holes. Lecture Notes in Physics. Springer 201

Modelling spectral and timing properties of accreting black holes: the hybrid hot flow paradigm

The general picture that emerged by the end of 1990s from a large set of optical and X-ray, spectral and timing data was that the X-rays are produced in the innermost hot part of the accretion flow, while the optical/infrared (OIR) emission is mainly produced by the irradiated outer thin accretion disc. Recent multiwavelength observations of Galactic black hole transients show that the situation is not so simple. Fast variability in the OIR band, OIR excesses above the thermal emission and a complicated interplay between the X-ray and the OIR light curves imply that the OIR emitting region is much more compact. One of the popular hypotheses is that the jet contributes to the OIR emission and even is responsible for the bulk of the X-rays. However, this scenario is largely ad hoc and is in contradiction with many previously established facts. Alternatively, the hot accretion flow, known to be consistent with the X-ray spectral and timing data, is also a viable candidate to produce the OIR radiation. The hot-flow scenario naturally explains the power-law like OIR spectra, fast OIR variability and its complex relation to the X-rays if the hot flow contains non-thermal electrons (even in energetically negligible quantities), which are required by the presence of the MeV tail in Cyg X-1. The presence of non-thermal electrons also lowers the equilibrium electron temperature in the hot flow model to <100 keV, making it more consistent with observations. Here we argue that any viable model should simultaneously explain a large set of spectral and timing data and show that the hybrid (thermal/non-thermal) hot flow model satisfies most of the constraints.Comment: 26 pages, 13 figures. To be published in the Space Science Reviews and as hard cover in the Space Sciences Series of ISSI - The Physics of Accretion on to Black Holes (Springer Publisher

Dental Caries Experience in the Deciduous Dentition of Rural Guatemalan Children Ages 6 Months to 7 Years

A study of 528 Guatemalan children indicated that caries prevalence in the deciduous dentition was twice as great as but in the permanent dentition was similar to that for US white children. This is a repeated observation for children of some preindustrial societies. Caries experience was significantly greater in boys. Until 4 years of age, caries attack was greater in the anterior segment of the oral cavity; linear enamel hypoplasia was a predisposing factor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68238/2/10.1177_00220345760550064501.pd

A Pure-Glue Hidden Valley I. States and Decays

It is possible that the standard model is coupled, through new massive charged or colored particles, to a hidden sector whose low energy dynamics is controlled by a pure Yang-Mills theory, with no light matter. Such a sector would have numerous metastable "hidden glueballs" built from the hidden gluons. These states would decay to particles of the standard model. We consider the phenomenology of this scenario, and find formulas for the lifetimes and branching ratios of the most important of these states. The dominant decays are to two standard model gauge bosons, or by radiative decays with photon emission, leading to jet- and photon-rich signals.Comment: 34 pages, 4 figure