The role of EQA in harmonization in laboratory medicine – a global effort

There are many activities currently being undertaken in the field of laboratory medicine under the broad heading of “harmonization”. These include traceability of results to international reference standards, processes to align results from assays where traceability has not been achieved (analytical harmonization) and international or national clinical guidelines based on studies from many parts of the world. Many of these issues are global in nature, with clinical evidence derived from studies performed in all parts of the world and multinational diagnostic companies providing assays worldwide. As with all aspects of medicine, progress can only be assured where these is evidence of effectiveness of the activities. External Quality Assurance (EQA) programs are designed to meet this need. Currently EQA processes have significant limitations in meeting the global needs of the laboratory medicine community. This paper aims to identify the steps that can be taken to allow current and future EQA programs to provide information on global variation in results. It is only by being aware of result differences that steps can be taken to improve performanc

The <i>ENHANCED MAGNAPORTHE RESISTANCE 1</i> locus affects Ramularia leaf spot development in barley

Ramularia leaf spot (RLS) is a newly-important disease of barley which is caused when the fungus Ramularia collo-cygni enters necrotrophic development during colonisation of the host. Mutant alleles at the barley MILDEW LOCUS O, mlo, locus confer broad spectrum durable resistance against the powdery mildew fungus, Blumeria graminis f. sp. hordei, but can enhance susceptibility to pathogens with necrotrophic development stages such as R. collo-cygni. Given the importance of mlo in spring barley breeding programmes, identifying loci that mitigate the effect of mlo-mediated susceptibility on necrotrophic disease development is an important target. Mutation of the ENHANCED MAGNAPORTHE 1 (emr1) locus which can affect mlo-associated disease susceptibility, leads to a reduction in RLS symptoms on barley leaves but does not reduce R. collo-cygni accumulation. The effect of emr1 on the transition of R. collo-cygni from endophyte to necrotroph may relate to changes in reactive oxygen species in mutant plants which show reduced sensitivity to chloroplastic superoxide induced cell death and has lower relative chlorophyll content compared to mlo plants.</p

Serum vitamin D levels, diabetes and cardio-metabolic risk factors in Aboriginal and Torres Strait Islander Australians

Assesses levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and explores relationships between 25(OH)D and cardio-metabolic risk factors and diabetes. Abstract Background: Low levels of serum 25 – hydroxy vitamin D (25(OH)D), have been associated with development of type 2 diabetes and cardiovascular disease (CVD); however there are limited data on serum 25(OH)D in Indigenous Australians, a population at high risk for both diabetes and CVD. We aimed to assess levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and to explore relationships between 25(OH)D and cardio-metabolic risk factors and diabetes. Methods: 592 Aboriginal and/or Torres Strait Islander Australian participants of The eGFR (estimated glomerular filtration rate) Study, a cross-sectional analysis of a cohort study performed in 2007 – 2011, from urban and remote centres within communities, primary care and tertiary hospitals across Northern Territory, Far North Queensland and Western Australia. Assessment of serum 25(OH)D, cardio-metabolic risk factors (central obesity, diabetes, hypertension, history of cardiovascular disease, current smoker, low HDL-cholesterol), and diabetes (by history or HbA1c ≥ 6.5%) was performed. Associations were explored between 25(OH)D and outcome measures of diabetes and number of cardio-metabolic risk factors. Results: The median (IQR) serum 25(OH)D was 60 (45 – 77) nmol/L, 31% had 25(OH)D &lt;50 nmol/L. For participants with 25(OH)D &lt; 50 vs ≥ 50 nmol/L, cardio-metabolic risk profile differed for: diabetes (54%, 36% p &lt; 0.001), past history of cardiovascular disease (16%, 9%, p = 0.014), waist-hip ratio (0.98, 0.92, p &lt; 0.001), urine albumin-creatinine ratio (2.7, 1.5 mg/mmol, p &lt; 0.001). The OR (95% CI) for diabetes was 2.02 (1.03 – 3.95) for people in the lowest vs highest tertiles of 25(OH)D (&lt;53 vs &gt;72 nmol/L, respectively) after adjusting for known cardio-metabolic risk factors. Conclusion: The percentage of 25(OH)D levels &lt;50 nmol/L was high among Aboriginal and Torres Strait Islander Australians from Northern and Central Australia. Low 25(OH)D level was associated with adverse cardio-metabolic risk profile and was independently associated with diabetes. These findings require exploration in longitudinal studies

Responding to the Event Deluge

We present the VOEventNet infrastructure for large-scale rapid follow-up of astronomical events, including selection, annotation, machine intelligence, and coordination of observations. The VOEvent standard is central to this vision, with distributed and replicated services rather than centralized facilities. We also describe some of the event brokers, services, and software that are connected to the network. These technologies will become more important in the coming years, with new event streams from Gaia, LOFAR, LIGO, LSST, and many others.Comment: Submitted to Proceedings of SPIE Observatory Operations, Amsterdam, 2012 July 2-

Geochemical analysis of bulk marine sediment by Inductively Coupled Plasma–Atomic Emission Spectroscopy on board the JOIDES Resolution

Geochemical analyses on board the JOIDES Resolution have been enhanced with the addition of a Jobin-Yvon Ultrace inductively coupled plasma-atomic emission spectrometer (ICP-AES) as an upgrade from the previous X-ray fluorescence facility. During Leg 199, we sought to both challenge and utilize the capabilities of the ICP-AES in order to provide an extensive bulk-sediment geochemical database during the cruise. These near real-time analyses were then used to help characterize the recovered sedimentary sequences, calculate mass accumulation rates of the different sedimentary components, and assist with cruise and postcruise sampling requests. The general procedures, sample preparation techniques, and basic protocol for ICP-AES analyses on board ship are outlined by Murray et al. (2000) in Ocean Drilling Program Tech Note, 29. We expand on those concepts and offer suggestions for ICP-AES methodology, calibration by standard reference materials, data reduction procedures, and challenges that are specific to the analysis of bulk-sediment samples. During Leg 199, we employed an extensive bulk-sediment analytical program of ~600 samples of varying lithologies, thereby providing several opportunities for refinement of techniques. We also discuss some difficulties and challenges that were faced and suggest how to alleviate such occurrences for sedimentary chemical analyses during future legs

Transport time scales in soil erosion modelling

Unlike sediment transport in rivers, erosion of agricultural soil must overcome its cohesive strength to move soil particles into suspension. Soil particle size variability also leads to fall velocities covering many orders of magnitude, and hence to different suspended travel distances in overland flow. Consequently, there is a large range of inherent time scales involved in transport of eroded soil. For conditions where there is a constant rainfall rate and detachment is the dominant erosion mechanism, we use the Hairsine-Rose (HR) model to analyze these timescales, to determine their magnitude (bounds) and to provide simple approximations for them. We show that each particle size produces both fast and slow timescales. The fast timescale controls the rapid adjustment away from experimental initial conditions – this happens so quickly that it cannot be measured in practice. The slow time scales control the subsequent transition to steady state and are so large that true steady state is rarely achieved in laboratory experiments. Both the fastest and slowest time scales are governed by the largest particle size class. Physically, these correspond to the rate of vertical movement between suspension and the soil bed, and the time to achieve steady state, respectively. For typical distributions of size classes, we also find that there is often a single dominant time scale that governs the growth in the total mass of sediment in the non-cohesive deposited layer. This finding allows a considerable simplification of the HR model leading to analytical expressions for the evolution of suspended and deposited layer concentrations

Gamma-ray and radio tests of the e+e- excess from DM annihilations

PAMELA and ATIC recently reported an excess in e+e- cosmic rays. We show that if it is due to Dark Matter annihilations, the associated gamma-ray flux and the synchrotron emission produced by e+e- in the galactic magnetic field violate HESS and radio observations of the galactic center and HESS observations of dwarf Spheroidals, unless the DM density profile is significantly less steep than the benchmark NFW and Einasto profiles.Comment: 16 pages, 4 figures; v2: normalizations fixed in Table 2 and typos corrected (no changes in the analysis nor the results), some references and comments added; v3: minor additions, matches published versio

Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or

The Fueling and Evolution of AGN: Internal and External Triggers

In this chapter, I review the fueling and evolution of active galactic nuclei (AGN) under the influence of internal and external triggers, namely intrinsic properties of host galaxies (morphological or Hubble type, color, presence of bars and other non-axisymmetric features, etc) and external factors such as environment and interactions. The most daunting challenge in fueling AGN is arguably the angular momentum problem as even matter located at a radius of a few hundred pc must lose more than 99.99 % of its specific angular momentum before it is fit for consumption by a BH. I review mass accretion rates, angular momentum requirements, the effectiveness of different fueling mechanisms, and the growth and mass density of black BHs at different epochs. I discuss connections between the nuclear and larger-scale properties of AGN, both locally and at intermediate redshifts, outlining some recent results from the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte