434 research outputs found

    Quantification of phosphorus loss from soil to water.

    Get PDF
    End of Project ReportThe methods, results and discussion of the project are in five separate sections, 4.1) Phosphorus (P) export from agricultural grassland with overland flow and drainage water (Johnstown Castle); 4.2) Phosphorus export from farm in Dripsey catchment, Co. Cork (NMP); 4.3) Hydrometeorological aspects of farm in Dripsey Catchment (NMP); 4.4) Phosphorus desorption from Irish soils; 4.5) National phosphorus model. Most of the field and laboratory studies were carried out at Johnstown Castle, at UCC and the field site in the Dripsey catchment. The main aim of the project was to quantify the loss of P from soil to water where point source contributions from farmyards were not high. This involved the construction of hydrologically isolated field sites where the quantity of overland flow and the P concentrations for different runoff events from the fields could be measured. In addition, 90 soil samples representative of Irish soils were collected and analysed for the different factors influencing soil adsorption and desorption of P. These results, in addition to catchment data, were used as a first attempt at developing a model that could be used to help predict P loss from soil to water at a catchment scale. The study in the Dripsey was on a farm where water flow and P levels at two points in a stream were measured. The hydrometeorology at this site was also studied. At Johnstown Castle, three overland flow sites, of the order of one hectare each, and one subsurface flow site were studied for P loss to water.Environmental Protection Agency

    THE INTERPLAY OF THE K+K- ATOM AND THE f_0(975) RESONANCE

    Full text link
    We predict that production of the K+K- atom in pd-3^HeX and similar reactions exhibits a drastic missing mass spectrum due to the interplay with f_0(975) resonance. We point out that high precision studies of the K+K- atom may shed a new light on the nature of f_0(975).Comment: 13 page

    Some general properties of the renormalized stress-energy tensor for static quantum states on (n+1)-dimensional spherically symmetric black holes

    Get PDF
    We study the renormalized stress-energy tensor (RSET) for static quantum states on (n+1)-dimensional, static, spherically symmetric black holes. By solving the conservation equations, we are able to write the stress-energy tensor in terms of a single unknown function of the radial co-ordinate, plus two arbitrary constants. Conditions for the stress-energy tensor to be regular at event horizons (including the extremal and ``ultra-extremal'' cases) are then derived using generalized Kruskal-like co-ordinates. These results should be useful for future calculations of the RSET for static quantum states on spherically symmetric black hole geometries in any number of space-time dimensions.Comment: 9 pages, no figures, RevTeX4, references added, accepted for publication in General Relativity and Gravitatio

    Predicting large-scale habitat suitability for cetaceans off Namibia using MinxEnt

    Get PDF
    Knowledge of the occurrence and distribution of cetaceans is particularly important for conservation and management, but is still limited within Namibian waters. We collated 3211 cetacean records from the Namibian Exclusive Economic Zone (EEZ) for the period 2008 to 2016 and applied the principle of minimum cross entropy (MinxEnt) to predict habitat suitability. MinxEnt is a generalised form of maximum entropy modelling that allows incorporation of additional information such as sampling bias. The habitat suitability of 9 cetacean species or species groups (5 odontocete species, 2 mysticete species and 2 taxonomic groups: pilot whales Globicephalus spp. and balaenopterids Balaenopteridae spp.) were predicted per season, in relation to environmental variables likely to drive cetacean presence: sea surface temperature, chlorophyll a concentration, water depth or distance to shore, seabed slope and habitat complexity. The environmental variable which most frequently influenced habitat suitability was depth, which was the main environmental driver for bottlenose dolphin Tursiops truncatus, humpback Megaptera novaeangliae and southern right whales Eubalaena australis. Further, Heaviside’s dolphin Cephalorhynchus heavisidii habitat was best predicted by distance to shore in all seasons, while common dolphin Delphinus delphis and the balaenopterid group habitats were best predicted by habitat complexity, and sperm whale Physeter macrocephalus habitats by chlorophyll a concentration. We identify distinct spatial patterns in habitat suitability for different species and provide baseline maps which can be used by managers of wildlife resources.R.H.L. and aerial surveys were funded by the British Ecological Society and the Mohammed Bin Zayed Species Conservation Fund.http://www.int-res.com/journals/meps/meps-home2024-06-04hj2019Mammal Research InstituteZoology and Entomolog

    Safety and Immunogenicity of a Recombinant Adenovirus Serotype 35-Vectored HIV-1 Vaccine in Adenovirus Serotype 5 Seronegative and Seropositive Individuals.

    Get PDF
    BACKGROUND: Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. METHODS: HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. RESULTS: All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. CONCLUSIONS: Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted

    Tomato: a crop species amenable to improvement by cellular and molecular methods

    Get PDF
    Tomato is a crop plant with a relatively small DNA content per haploid genome and a well developed genetics. Plant regeneration from explants and protoplasts is feasable which led to the development of efficient transformation procedures. In view of the current data, the isolation of useful mutants at the cellular level probably will be of limited value in the genetic improvement of tomato. Protoplast fusion may lead to novel combinations of organelle and nuclear DNA (cybrids), whereas this technique also provides a means of introducing genetic information from alien species into tomato. Important developments have come from molecular approaches. Following the construction of an RFLP map, these RFLP markers can be used in tomato to tag quantitative traits bred in from related species. Both RFLP's and transposons are in the process of being used to clone desired genes for which no gene products are known. Cloned genes can be introduced and potentially improve specific properties of tomato especially those controlled by single genes. Recent results suggest that, in principle, phenotypic mutants can be created for cloned and characterized genes and will prove their value in further improving the cultivated tomato.

    Recalibration of the limiting antigen avidity EIA to determine mean duration of recent infection in divergent HIV-1 subtypes.

    Get PDF
    ArticleBackground: Mean duration of recent infection (MDRI) and misclassification of long-term HIV-1 infections, as proportion false recent (PFR), are critical parameters for laboratory-based assays for estimating HIV-1 incidence. Recent review of the data by us and others indicated that MDRI of LAg-Avidity EIA estimated previously required recalibration. We present here results of recalibration efforts using >250 seroconversion panels and multiple statistical methods to ensure accuracy and consensus. Methods: A total of 2737 longitudinal specimens collected from 259 seroconverting individuals infected with diverse HIV-1 subtypes were tested with the LAg-Avidity EIA as previously described. Data were analyzed for determination of MDRI at ODn cutoffs of 1.0 to 2.0 using 7 statistical approaches and sub-analyzed by HIV-1 subtypes. In addition, 3740 specimens from individuals with infection >1 year, including 488 from patients with AIDS, were tested for PFR at varying cutoffs. Results: Using different statistical methods,MDRI values ranged from 88-94 days at cutoff ODn = 1.0 to 177-183 days at ODn = 2.0. The MDRI values were similar by different methods suggesting coherence of different approaches. Testing formisclassification among long-terminfections indicated that overall PFRs were 0.6%to 2.5%at increasing cutoffs of 1.0 to 2.0, respectively. Balancing the need for a longer MDRI and smaller PFR (<2.0%) suggests that a cutoff ODn = 1.5, corresponding to an MDRI of 130 days should be used for cross-sectional application. The MDRI varied among subtypes from 109 days (subtype A&D) to 152 days (subtype C). Conclusions: Based on the new data and revised analysis, we recommend an ODn cutoff = 1.5 to classify recent and long-term infections, corresponding to an MDRI of 130 days (118-142). Determination of revised parameters for estimation of HIV-1 incidence should facilitate application of the LAg-Avidity EIA for worldwide use.This research has been supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through the Centers for Disease Control and Prevention (CDC)

    Existence of the σ\sigma-meson below 1 GeV and f0(1500)f_0(1500) glueball

    Full text link
    On the basis of a simultaneous description of the isoscalar s-wave channel of the ππ\pi\pi scattering (from the threshold up to 1.9 GeV) and of the ππKKˉ\pi\pi\to K\bar{K} process (from the threshold to \sim 1.4 GeV) in the model-independent approach, a confirmation of the σ\sigma-meson at \sim 665 MeV and an indication for the glueball nature of the f0(1500)f_0(1500) state are obtained. It is shown that the large ππ\pi\pi-background, usually obtained, combines, in reality, the influence of the left-hand branch-point and the contribution of a very wide resonance at \sim 665 MeV. The coupling constants of the observed states with the ππ\pi\pi and KKˉK\bar{K} systems and lengths of the ππ\pi\pi and KKˉK\bar{K} scattering are obtained.Comment: 13 pages, 3 figures, LaTex; submitted to Physics Letters
    corecore