1,008 research outputs found

    Improving supply and phosphorous use efficiency in organic farming systems

    Get PDF
    Phosphorus (P) is an essential plant nutrient that needs to be managed carefully in organic systems so that crop yield and quality remain sustainable without contributing to environmental damage, particularly that associated with eutrophication. Under organic regulations, minimally processed rock phosphate (PR) can be used to amend low P fertility soils, although the solubility is extremely low at optimum soil pH for most crop growth (pH 6.5). This paper describes a project (PLINK) which aims to develop methods of improving P efficiency on organic farms, although the same approaches may also be applicable on conventional and low-input farms. The methodologies that the project is developing include the fermentation and composting of crop waste material with PR in order to solubilise P and make it more available to the crop. Some initial results are described here. In addition, the project will investigate the alteration of the rotation to include crops or varieties with high P uptake efficiency, or roots that possess acidifying properties which improve P availability for following crops

    Indicator systems - resource use in organic systems

    Get PDF
    A balanced use of resources within organic farming systems is required to maintain sustainable systems. Hence, it is essential to have tools that can assess the use of resources within the farming system and their impact on the environment. The range of tools that have been developed include those assessing local farm-scale issues together with those that assess impacts at the global scale. At the global scale assessments are usually made on the basis of a unit of product whereas at the local scale assessments can also be made on an area basis. In addition, the tools also assess a variety of issues, e.g. biodiversity, pollution potential, energy and water use. The level of detail required for the different assessment tools differs substantially; nevertheless it is essential that the indicator systems developed are based on sound knowledge, are acceptable to the farmers and can guide their future actions

    Photometric study of southern SU UMa-type dwarf novae and candidates -- III: NSV 10934, MM Sco, AB Nor, CAL 86

    Full text link
    We photometrically observed four southern dwarf novae in outburst (NSV 10934, MM Sco, AB Nor and CAL 86). NSV 10934 was confirmed to be an SU UMa-type dwarf nova with a mean superhump period of 0.07478(1) d. This star also showed transient appearance of quasi-periodic oscillations (QPOs) during the final growing stage of the superhumps. Combined with the recent theoretical interpretation and with the rather unusual rapid terminal fading of normal outbursts, NSV 10934 may be a candidate intermediate polar showing SU UMa-type properties. The mean superhump periods of MM Sco and AB Nor were determined to be 0.06136(4) d and 0.08438(2) d, respectively. We suggest that AB Nor belongs to a rather rare class of long-period SU UMa-type dwarf novae with low mass-transfer rates. We also observed an outburst of the suspected SU UMa-type dwarf nova CAL 86. We identified this outburst as a normal outburst and determined the mean decline rate of 1.1 mag/d.Comment: 13 pages, 23 figures, to appear in MNRAS. For more information, see http://www.kusastro.kyoto-u.ac.jp/vsnet

    Review of outside pathology prior to treatment of cervical intraepithelial neoplasia: a cost analysis

    Get PDF
    Objectives: Academic institutions routinely require in-house review of pathology prior to treatment. However, it is unclear if pathology review is beneficial for the management of patients referred for cervical intraepithelial neoplasia (CIN). This study aims to determine if review of outside pathology for CIN at an academic medical center resulted in a change in the treatment plan and the associated cost for pathology review. Methods: A retrospective chart review of patients referred for treatment of CIN, including review of outside cytology and histology was performed from January 1 to December 31, 2007 after obtaining IRB approval. Data was analyzed to determine whether pathology diagnosis was changed from the outside facility interpretation; classified as minor if there was no change in clinical management and major if there was a change in treatment as a result of the internal review. Demographic and pathology information was collected from electronic medical records. Billing information was collected from the finance department. Data were analyzed using descriptive statistics. Results: Seventy-eight patients were identified of which 54 had outside pathology slides available for pathology review. Eleven had a minor change in the pathology diagnosis (20%). None of the changes in pathology diagnosis resulted in a change in treatment plan (major). The total pathology review charge was 14,679forthe54patients,withanaveragechargeperpatientof14,679 for the 54 patients, with an average charge per patient of 272. Nine of the cases were charged twice to reflect the opinion of two separate pathologists (internal consultation). Of the 54 patients, 23 (43%) had state supported insurance, 24 (44%) had private insurance, and 7 (13%) were self-pay. A total of $12,969.29 was not covered/paid (88% of all charges) and thus absorbed by the institution. Conclusion: Mandatory review of outside pathology is a common practice. However, it may not be beneficial in all clinical situations. While this pathology review for CIN resulted in minor changes for 20% of patients referred to our academic/tertiary institution, it did not affect any treatment recommendations. Pathology review did increase the cost burden to the institution and the patient

    ΦCrAss001 represents the most abundant bacteriophage family in the human gut and infects Bacteroides intestinalis

    Get PDF
    peer-reviewedCrAssphages are an extensive and ubiquitous family of tailed bacteriophages, predicted to infect bacteria of the order Bacteroidales. Despite being found in ~50% of individuals and representing up to 90% of human gut viromes, members of this viral family have never been isolated in culture and remain understudied. Here, we report the isolation of a CrAssphage (ΦCrAss001) from human faecal material. This bacteriophage infects the human gut symbiont Bacteroides intestinalis, confirming previous in silico predictions of the likely host. DNA sequencing demonstrates that the bacteriophage genome is circular, 102 kb in size, and has unusual structural traits. In addition, electron microscopy confirms that ΦcrAss001 has a podovirus-like morphology. Despite the absence of obvious lysogeny genes, ΦcrAss001 replicates in a way that does not disrupt proliferation of the host bacterium, and is able to maintain itself in continuous host culture during several weeks

    A Study of Compact Radio Sources in Nearby Face-on Spiral Galaxies. II. Multiwavelength Analyses of Sources in M51

    Get PDF
    We report the analysis of deep radio observations of the interacting galaxy system M51 from the Very Large Array, with the goal of understanding the nature of the population of compact radio sources in nearby spiral galaxies. We detect 107 compact radio sources, 64% of which have optical counterparts in a deep Hα\alpha Hubble Space Telescope image. Thirteen of the radio sources have X-ray counterparts from a {\em Chandra} observation of M51. We find that six of the associated Hα\alpha sources are young supernova remnants with resolved shells. Most of the SNRs exhibit steep radio continuum spectral indices onsistent with synchrotron emission. We detect emission from the Type Ic SN 1994I nearly a decade after explosion: the emission (160±22μ160\pm22 \muJy beam1^{-1} at 20 cm, 46±11μ46\pm11 \muJy beam1^{-1} at 6cm, α=1.02±0.28\alpha=-1.02\pm0.28) is consistent with light curve models for Type Ib/Ic supernovae. We detect X-ray emission from the supernova, however no optical counterpart is present. We report on the analysis of the Seyfert 2 nucleus in this galaxy, including the evidence for bipolar outflows from the central black hole.Comment: 22 pages, 8 figures (5 color) in separate files, AASTeX. Full resolution figures and preprint may be obtained by contacting [email protected]. AJ accepte

    Relationships Between the Nutrient Content of Irrigated Pasture on Offer and that Selected by Grazing Dairy Cows

    Get PDF
    An experiment was conducted to determine the dry matter, energy, crude protein and fibre intake by dairy cows in late lactation when grazing perennial pasture offered at allocations of 15, 20, 30 and 40 kg DM/cow.day. The cows consistently selected a diet 10% higher in digestibility than that on offer. In contrast, cows selected diets with crude protein levels increasing from 22% to 40%, above that in pasture on offer, as pasture allocation increased. A similar pattern was observed for the intake of white clover (Trifolium repens L). The increase in the concentration of crude protein in the diet (as allocation increased) was due to the consumption of white clover and a decrease in the consumption of the dead components of the sward. On the other hand, the neutral detergent fibre content of the diet selected was lower than that on offer, and declined as pasture allocation increased

    23 GHz VLBI Observations of SN 2008ax

    Get PDF
    We report on phase-referenced 23 GHz Very-Long-Baseline-Interferometry (VLBI) observations of the type IIb supernova SN 2008ax, made with the Very Long Baseline Array (VLBA) on 2 April 2008 (33 days after explosion). These observations resulted in a marginal detection of the supernova. The total flux density recovered from our VLBI image is 0.8±\pm0.3 mJy (one standard deviation). As it appears, the structure may be interpreted as either a core-jet or a double source. However, the supernova structure could be somewhat confused with a possible close by noise peak. In such a case, the recovered flux density would decrease to 0.48±\pm0.12 mJy, compatible with the flux densities measured with the VLA at epochs close in time to our VLBI observations. The lowest average expansion velocities derived from our observations are (1.90±0.30)×105(1.90 \pm 0.30) \times 10^5 km s1^{-1} (case of a double source) and (5.2±1.3)×104(5.2 \pm 1.3) \times 10^4 km s1^{-1} (taking the weaker source component as a spurious, close by, noise peak, which is the more likely interpretation). These velocities are 7.3 and 2 times higher, respectively, than the maximum ejecta velocity inferred from optical-line observations.Comment: 4 pages, 3 figures. Accepted in A&A on 24/03/200

    Plant and Sward Characteristics to Achieve High Intake in Ruminants

    Get PDF
    Key points Intake is affected by complex interactions between signals from the digestive tract, intermediary metabolism and energy supply, and behavioural signals associated with learned behaviours or sensory signals. The ideal sward needs to have characteristics that are similar to total mixed rations to achieve high intake and animal performance. Genetic manipulation of plants may offer an accelerated rate of plant improvement, but benefits need to be demonstrated in a systems context

    A Study of Compact Radio Sources in Nearby Face-on Spiral Galaxies. I. Long Term Evolution of M83

    Full text link
    We present analyses of deep radio observations of M83 taken with the Very Large Array spanning fifteen years, including never before published observations from 1990 and 1998. We report on the evolution of 55 individual point sources, which include four of the six known historical supernovae in this galaxy. A total of 10 sources have X-ray counterparts from a {\em Chandra} survey. Each of these sources show non-thermal spectral indices, and most appear to be X-ray supernova remnants. Comparing the radio source list to surveys in optical and X-ray, we identify three optical/X-ray supernova remnants. Nearly half of the detected radio sources in these observations are coincident with known H II regions lying in the spiral arm structures of the galaxy. We also report on changes in emission from the complex nuclear region, which has shown variability at 20cm wavelengths. We confirm that the peak radio emission from the nucleus is not coincident with the known optical center. One lesser nuclear peak is consistent with the optical/IR nucleus. Previous dynamical studies of a ``dark'' nuclear mass indicate a possible match to other radio nuclear emission regions in M83.Comment: 32 Pages, 8 figures, to appear in AJ. Full resolution figures can be obtained at http://nhn.ou.edu/~maddo
    corecore