Unrecognized pollutant risks to the Great Barrier Reef

This report summarises the occurrence, distribution, risks and toxicity of ten pollutants to the marine environment: marine debris, microplastics, sewage-sourced contaminants, trace metals, anti-foulants, coal dust, petroleum hydrocarbon contaminants, flame retardants, polychlorinated biphenyls (PCBs) and non-photosystem II (PSII) pesticides

Preadolescent children's perception of power imbalance in bullying: A thematic analysis

Bullying in schools is associated with an extensive public health burden. Bullying is intentional and goal oriented aggressive behavior in which the perpetrator exploits an imbalance of power to repeatedly dominate the victim. To differentiate bullying from aggressive behavior, assessment must include a valid measure of power imbalance as perceived by the victim. And yet, to date, there remains no agreement as to how to most accurately measure power imbalance among preadolescent children. This qualitative study explored children's (age 9 to 11) understanding of power imbalance through thematic analysis of focus group discussions. Subthemes that emerged as influencing power imbalance include: Age of victim, peer valued characteristics, and group membership and position. Subthemes of empathy and peer valued characteristics emerged as protecting against the negative impact of power imbalance

We Want to Know: Eliciting Hospitalized Patients' Perspectives on Breakdowns in Care

BACKGROUND: There is increasing recognition that patients have critical insights into care experiences, including breakdowns in care. Harnessing patient perspectives for hospital improvement requires an in-depth understanding of the types of breakdowns patients identify and the impact of these events. METHODS: We interviewed a broad sample of patients during hospitalization and post discharge to elicit patient perspectives on breakdowns in care. Through an iterative process, we developed a categorization of patient-perceived breakdowns called the Patient Experience Coding Tool. RESULTS: Of 979 interviewees, 386 (39.4%) believed they had experienced at least one breakdown in care. The most common reported breakdowns involved information exchange (n = 158, 16.1%), medications (n = 120, 12.3%), delays in admission (n = 90, 9.2%), team communication (n = 65, 6.6%), providers’ manner (n = 62, 6.3%), and discharge (n = 56, 5.7%). Of the 386 interviewees who reported a breakdown, 140 (36.3%) perceived associated harm. Patient-perceived harms included physical (eg, pain), emotional (eg, distress, worry), damage to relationship with providers, need for additional care or prolonged hospital stay, and life disruption. We found higher rates of reporting breakdowns among younger (<60 years old) patients (45.4% vs 34.5%, P < 0.001), those with at least some college education (46.8% vs 32.7%, P < 0.001), and those with another person (family or friend) present during the interview or interviewed in lieu of the patient (53.4% vs 37.8%, P = 0.002). CONCLUSIONS: When asked directly, almost 4 out of 10 hospitalized patients reported a breakdown in their care. Patient-perceived breakdowns in care are frequently associated with perceived harm, illustrating the importance of detecting and addressing these events. Journal of Hospital Medicine 2017;12:603-609. © 2017 Society of Hospital Medicin

Mice with a deletion of Rsph1 exhibit a low level of mucociliary clearance and develop a primary ciliary dyskinesia phenotype

Primary ciliary dyskinesia (PCD) is a genetically and phenotypically heterogeneous disease caused by mutations in over 40 different genes. Individuals with PCD caused by mutations in RSPH1 (radial spoke head 1 homolog) have been reported to have a milder phenotype than other individuals with PCD, as evidenced by a lower incidence of neonatal respiratory distress, higher nasal nitric oxide concentrations, and better lung function. To better understand genotype-phenotype relationships in PCD, we have characterized a mutant mouse model with a deletion of Rsph1. Approximately 50% of cilia from Rsph1-/- cells appeared normal by transmission EM, whereas the remaining cilia revealed a range of defects, primarily transpositions or a missing central pair. Ciliary beat frequency in Rsph1-/- cells was significantly lower than in control cells (20.2±0.8 vs. 25.0±0.9 Hz), and the cilia exhibited an aberrant rotational waveform. Young Rsph1-/- animals demonstrated a low rate of mucociliary clearance in the nasopharynx that was reduced to zero by about 1 month of age. Rsph1-/- animals accumulated mucus in the nasal cavity but had a lower bacterial burden than animals with a deletion of dynein axonemal intermediate chain 1 (Dnaic1-/-). Thus, Rsph1-/- mice display a PCD phenotype similar to but less severe than that observed in Dnaic1-/- mice, similar to what has been observed inhumans. The results suggest that some individuals with PCD may not have a complete loss of mucociliary clearance and further suggest that early diagnosis and intervention may be important to maintain this low amount of clearance

K\"{a}hler-Einstein metrics on strictly pseudoconvex domains

The metrics of S. Y. Cheng and S.-T. Yau are considered on a strictly pseudoconvex domains in a complex manifold. Such a manifold carries a complete K\"{a}hler-Einstein metric if and only if its canonical bundle is positive. We consider the restricted case in which the CR structure on $\partial M$ is normal. In this case M must be a domain in a resolution of the Sasaki cone over $\partial M$. We give a condition on a normal CR manifold which it cannot satisfy if it is a CR infinity of a K\"{a}hler-Einstein manifold. We are able to mostly determine those normal CR 3-manifolds which can be CR infinities. Many examples are given of K\"{a}hler-Einstein strictly pseudoconvex manifolds on bundles and resolutions.Comment: 30 pages, 1 figure, couple corrections, improved a couple example

Iron and vitamin interactions in marine diatom isolates and natural assemblages of the Northeast Pacific Ocean

Trace metals and B-vitamins play critical roles in regulating marine phytoplankton growth and composition. While some microorganisms are capable of producing certain B-vitamins, others cannot synthesize them and depend on an exogenous supply. Therefore, external factors influencing vitamin synthesis, such as micronutrient concentrations, alter the extent to which B-vitamins are available to auxotrophs in surface waters. We examined iron, B7 (biotin) and B12 (cobalamin) dynamics in diatoms through laboratory culture experiments and within natural diatom assemblages present along an iron gradient in the Northeast Pacific Ocean. In laboratory cultures of the diatom Pseudo-nitzschia granii, biotin synthase (BIOB) expression decreased 2-fold under iron limitation, suggesting iron status may affect B7 production in diatoms. Additionally in laboratory cultures of the diatom Grammonema cf. islandica, which contains a B12-independent methionine synthase (METE), a 15-fold increase in the expression of METE was observed when grown in the absence of B12 with no significant influence of iron status, suggesting METE expression can be driven by B12 status alone. Iron and B-vitamin amendment experiments with natural diatom assemblages in iron-limited waters of the Northeast Pacific Ocean provide evidence for vitamin-associated molecular responses that suggest elevated B7 biosynthesis and the emergence of B12 limitation following iron addition. Furthermore B-vitamin gene modules comprised of partial and/or complete B-vitamin biosynthetic pathways in diatoms increased in response to iron addition, including genes potentially involved in the processing of B12 intermediates. Our results indicate that vitamins may play an important role in regulating phytoplankton growth and composition in this region, particularly following natural iron addition events

Cytoplasmic “ciliary inclusions” in isolation are not sufficient for the diagnosis of primary ciliary dyskinesia

Background: The diagnosis of primary ciliary dyskinesia (PCD) is difficult and requires a combination of clinical features, nasal nitric oxide testing, cilia ultrastructural analysis by electron microscopy (EM), and genetics. A recently described cytoplasmic ultrastructural change termed “ciliary inclusions” was reported to be diagnostic of PCD; however, no supporting evidence of PCD was provided. In this study, we sought to confirm, or refute, the diagnosis of PCD in subjects with “ciliary inclusions” on EM. Methods: Six subjects from five families with previous lab reports of “ciliary inclusions” on EMs of ciliated cells were identified and evaluated at a Genetic Disorders of Mucociliary Clearance Consortium site. We performed a detailed clinical history, nasal nitric oxide measurement, genetic testing including whole-exome sequencing (WES), and when possible, repeat ciliary EM study. Results: Only one of six subjects had multiple and persistent clinical features congruent with PCD. No subject had situs inversus. Only one of six subjects had a very low nasal nitric oxide level. No “ciliary inclusions” were found in three subjects who had a repeat ciliary EM, and ciliary axonemal ultrastructures were normal. Genetic testing, including WES, was negative for PCD-causing genes, and for pathogenic variants in gene pathways that might cause “ciliary inclusions,” such as ciliary biogenesis. Conclusion: “Ciliary Inclusions”, in isolation, are not sufficient to diagnosis PCD. If seen, additional studies should be done to pursue an accurate diagnosis

Phenomenology of Pc(4380)+, Pc(4450)+ and related states

The $P_c(4380)^+$ and $P_c(4450)^+$ states recently discovered at LHCb have masses close to several relevant thresholds, which suggests they can be described in terms of meson-baryon degrees of freedom. This article explores the phenomenology of these states, and their possible partners, from this point of view. Competing models can be distinguished by the masses of the neutral partners which have yet to be observed, and the existence or otherwise of further partners with different isospin, spin, and parity. Future experimental studies in different decay channels can also discriminate among models, using selection rules and algebraic relations among decays. Among the several possible meson-baryon pairs which could be important, one implies that the states are mixtures of isospins 1/2 and 3/2, with characteristic signatures in production and decay. A previous experimental study of a Cabibbo-suppressed decay showed no evidence for the states, and further analysis is required to establish the significance of this non-observation. Several intriguing similarities suggest that $P_c(4450)^+$ is related to the $X(3872)$ meson.Comment: 16 pages, 1 figure. Journal version (some very minor changes from arXiv v1

Minimum Energy Configurations in the NN-Body Problem and the Celestial Mechanics of Granular Systems

Minimum energy configurations in celestial mechanics are investigated. It is shown that this is not a well defined problem for point-mass celestial mechanics but well-posed for finite density distributions. This naturally leads to a granular mechanics extension of usual celestial mechanics questions such as relative equilibria and stability. This paper specifically studies and finds all relative equilibria and minimum energy configurations for $N=1,2,3$ and develops hypotheses on the relative equilibria and minimum energy configurations for $N\gg 1$ bodies.Comment: Accepted for publication in Celestial Mechanics and Dynamical Astronom

Long-term evolution of orbits about a precessing oblate planet. 3. A semianalytical and a purely numerical approach

Construction of a theory of orbits about a precessing oblate planet, in terms of osculating elements defined in a frame of the equator of date, was started in Efroimsky and Goldreich (2004) and Efroimsky (2005, 2006). We now combine that analytical machinery with numerics. The resulting semianalytical theory is then applied to Deimos over long time scales. In parallel, we carry out a purely numerical integration in an inertial Cartesian frame. The results agree to within a small margin, for over 10 Myr, demonstrating the applicability of our semianalytical model over long timescales. This will enable us to employ it at the further steps of the project, enriching the model with the tides, the pull of the Sun, and the planet's triaxiality. Another goal of our work was to check if the equinoctial precession predicted for a rigid Mars could have been sufficient to repel the orbits away from the equator. We show that for low initial inclinations, the orbit inclination reckoned from the precessing equator of date is subject only to small variations. This is an extension, to non-uniform precession given by the Colombo model, of an old result obtained by Goldreich (1965) for the case of uniform precession and a low initial inclination. However, near-polar initial inclinations may exhibit considerable variations for up to +/- 10 deg in magnitude. Nevertheless, the analysis confirms that an oblate planet can, indeed, afford large variations of the equinoctial precession over hundreds of millions of years, without repelling its near-equatorial satellites away from the equator of date: the satellite inclination oscillates but does not show a secular increase. Nor does it show secular decrease, a fact that is relevant to the discussion of the possibility of high-inclination capture of Phobos and Deimos