2,367 research outputs found

    Presence of a clostero-like virus and a bacilliform virus in pineapple plants in Australia

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    When sap of asymptomatic or mealybug wilt-affected pineapple plants of the Smooth Cayenne group was negatively stained and examined in an electron microscope, clostero-like virus particles were occasionally seen. However, numerous clostero-like virus particles and occasionally some bacilliform particles were seen in partially purified preparations from both asymptomatic and wilted pineapple leaves. An antiserum, made by injecting partially purified preparations of clostero-like particles into a rabbit, trapped and decorated the clostero-like particles. Using this antiserum, the clostero-like particles (c. 1700 -1900x12 nm) were found in almost all plants tested of Smooth Cayenne selections C10, C13, C30 and F-180, the hybrid cv. 53-116 and a selection of the rough leaf Queen group. The particles were more readily trapped from extracts of roots of hybrid cv. 53-116 and Smooth Cayenne selection C10 than from leaves, crowns and fruits. They were not detected in seedlings of a cross between a Queen selection and the Smooth Cayenne selection C10. The clostero-like particles are similar to those reported to occur in pineapple plants in Hawaii and South Africa. This is the first report of their occurrence in Australia. Trapping and decoration tests of particles in pineapples in quarantine from Brazil, France, Malaysia and Taiwan indicated that a similar clostero-like virus occurs in all these countries. The bacilliform particles measured about 133x33 nm. They were trapped and decorated by the Queensland pineapple virus antiserum and also by an antiserum to sugarcane bacilliform badnavirus. They were detected occasionally in various smooth leaf and rough leaf pineapples in north and south Queensland and northern New South Wales. However, in one commercial planting of Smooth Cayenne selection C10 in south Queensland, bacilliform particles were trapped from 29/47 plants. This is the first report of a small bacilliform virus, probably belonging to the badnavirus group, occurring in pineapple plants. The relationship of the clostero-like and bacilliform viruses to yield loss and mealybug wilt in pineapples is unknown

    Alpha decay and proton-neutron correlations

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    We study the influence of proton-neutron (p-n) correlations on alpha-decay width. It is shown from the analysis of alpha Q values that the p-n correlations increase the penetration of the alpha particle through the Coulomb barrier in the treatment following Gamow's formalism, and enlarges the total alpha-decay width significantly. In particular, the isoscalar p-n interactions play an essential role in enlarging the alpha-decay width. The so-called "alpha-condensate" in Z > 84 isotopes are related to the strong p-n correlations.Comment: 5 pages, 6 figures, accepted for publication in Phys. Rev. C (R.C.

    A novel photonic crystal fibre switch

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    Thermal Decomposition of an Impure (Roxbury) Siderite: Relevance to the Presence of Chemically Pure Magnetite Crystals in ALH84001 Carbonate Disks

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    The question of the origin of nanophase magnetite in Martian meteorite ALH84001 has been widely debated for nearly a decade. Golden et al. have reported producing nearly chemically pure magnetite from thermal decomposition of chemically impure siderite [(Fe, Mg, Mn)CO3]. This claim is significant for three reasons: first, it has been argued that chemically pure magnetite present in the carbonate disks in Martian meteorite ALH84001 could have formed by the thermal decomposition of the impure carbonate matrix in which they are embedded; second, the chemical purity of magnetite has been previously used to identify biogenic magnetite; and, third, previous studies of thermal decomposition of impure (Mg,Ca,Mn)-siderites, which have been investigated under a wide variety of conditions by numerous researchers, invariably yields a mixed metal oxide phase as the product and not chemically pure magnetite. The explanation for this observation is that these siderites all possess the same crystallographic structure (Calcite; R3c) so solid solutions between these carbonates are readily formed and can be viewed on an atomic scale as two chemically different but structurally similar lattices

    Reimagine the ICU: Healthcare Professionals’ Perspectives on How Environments (Can) Promote Patient Well-Being

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    Objective: This study aims (1) to understand the needs and challenges of the current intensive care unit (ICU) environments in supporting patient well-being from the perspective of healthcare professionals (HCPs) and (2) to explore the new potential of ICU environments enabled by technology.Background: Evidence-based design has yielded how the design of environments can advocate for patient well-being, and digital technology offers new possibilities for indoor environments. However, the role of technology in facilitating ICU patient well-being has been unexplored.Method: This study was conducted in two phases. First, a mixed-method study was conducted with ICU HCPs from four Dutch hospitals. The study investigated the current environmental support for care activities, as well as the factors that positively and negatively contribute to patient experience. Next, a co-creation session was held involving HCPs and health technology experts to explore opportunities for technology to support ICU patient well-being.Results: The mixed-method study revealed nine negative and eight positive patient experience factors. HCPs perceived patient emotional care as most challenging due to the ICU workload and a lack of environmental support in fulfilling patient emotional needs. The co-creation session yielded nine technology-enabled solutions to address identified challenges. Finally, drawing from insights from both studies, four strategies were introduced that guide toward creating technology to provide holistic and personalized care for patients.Conclusion: Patient experience factors are intertwined, necessitating a multifactorial approach to support patient well-being. Viewing the ICU environment as a holistic unit, our findings provide guidance on creating healing environments using technology

    Origin of Magnetite Crystals in Martian Meteorite ALH84001 Carbonate Disks

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    Martian meteorite ALH84001 preserves evidence of interaction with aqueous fluids while on Mars in the form of microscopic carbonate disks which are believed to have precipitated approx.3.9 Ga ago at beginning of the Noachian epoch. Intimately associated within and throughout these carbonate disks are nanocrystal magnetites (Fe3O4) with unusual chemical and physical properties, whose origins have become the source of considerable debate. One group of hypotheses argues that these Fe3O4 are the product of partial thermal decomposition of the host carbonate. Alternatively, the origins of Fe3O4 and carbonate may be unrelated; that is, from the perspective of the carbonate the magnetite is allochthonous. We have sought to resolve between these hypotheses through the detailed characterized of the compositional and structural relationships of the carbonate disks and associated magnetites with the orthopyroxene matrix in which they are embedded [1]. We focus this discussion on the composition of ALH84001 magnetites and then compare these observations with those from our thermal decomposition studies of sideritic carbonates under a range of plausible geological heating scenarios

    An Analysis of MENA Region Economy Performance in Prevailing Global Economic Conditions

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    To survive in present volatile economic conditions is a herculean task. Global economic circumstances, socio political conditions play important role in growth and development of economies. Evaluating economies in prevailing condition requires effective approach and judicious analysis. All the major economies, developing and underdeveloped economies are performing below to their potential and are tilted to the downslide. MENA economy is struggling due to war disturbance and continuously performing below to its expectation and its overall growth touched the historic low. Its economy slowed down drastically and its GDP is below to world GDP. It’s fiscal and current deficits worsened and rose above 3 percent of the GDP, its oil exporters, public finance, public expenditure and job market, Banking system and FDI declined and facing high fiscal adjustments. In some parameters MENA economy is better than world set standards and in many it is far below. The carried out study is secondary data based and for the purpose authors evaluated and analysed the economic performance of MENA and tried to identify the risk factors which are potent enough to impact MENA economic growth. The outcome of the study revealed the fact that MENA economies are in intense heat and facing multiple economic complexities which translated into overall decline. In last conclusion has been given
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