544 research outputs found

    Sod-seeding for pasture rejuvenation: a review

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    Non-Peer ReviewedPasture productivity declines over time and producers need tools to rejuvenate pastures to restore productivity and ensure environmental and economic sustainability. Sod-seeding for pasture rejuvenation has been researched for 40 years in the region but little adoption of the technique has been observed. This review reports that water is a critical factor to successful seedling establishment after sod-seeding. The number of seedlings established was less in the Brown soil zone than in the Grey soil zone. However, more rainfall appears to be required for successful establishment in the Parkland than in the Prairie region. Removal of competition from the existing plants by herbicide application prior to sod-seeding improves the successful establishment of new seedlings but frequently results in less forage production in the seeding year. Alfalfa (Medicago sativa L.) has been successfully seeded in all soil zones while cicer milkvetch (Astragalus cicer L.) has shown good success in the Parkland region. Research results with fertilizer application are limited but P fertilizer at seeding can provide for enhanced seedling growth and establishment. Seeding equipment was limiting in many older research studies with inadequate depth control and variable seed placement. Modern zero-till crop drills in the Canadian Prairies were developed for cereal and oilseed cropping but have the necessary penetration, depth control, minimal soil and litter disturbance and on-row packing to be used in sod-seeding. Spring or late fall (dormant) seeding dates are recommended for sod-seeding. Further research is suggested on alternative legume species and adaptation to water stress to improve our understanding of sod-seeding in the Canadian Prairies

    Distributions of young cephalopods in the tropical waters of Western Australia over two consecutive summers

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    Cephalopod paralarvae and juveniles were sampled with light traps deployed at the surface and deeper in the southern NW Shelf and on Ningaloo Reef off Western Australia during two consecutive summers. One cross shelf transect (Exmouth) was sampled in the late spring and summers of 1997/1998 (summer 1) and 1998/1999 (summer 2), and a second cross shelf transect (Thevenard) and a longshore transect (Ningaloo) along the Ningaloo Reef were sampled in summer 2. Species captured in the order of abundance were octopods, Photololigo sp., Sepioteuthis lessoniana, and Sthenoteuthis oualaniensis. Most were captured in shallow traps except for Photololigo sp., which was common in both shallow and deep traps with larger animals found in deeper water. The presence of Idiosepius pygmaeus in deep water off Ningaloo Reef revealed the species to be eurytopic, inhabiting a wider range of habitats than previously known. Photololigo sp. and S. lessoniana were more abundant inshore, and octopods were especially abundant on mid-depth stations of the Exmouth transect, probably because of the turbulent mixing and increased productivity there. Fewer S. oualaniensis were caught during the first summer on the Ningaloo transect (n = 5) than during the second summer (n = 79)

    Evaluation of a follow-up programme after curative resection for colorectal cancer

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    Frequent liver imaging can detect liver metastases from colorectal cancer at an asymptomatic stage. © 1999 Cancer Research Campaig

    Focused molecular analysis of small cell lung cancer: feasibility in routine clinical practice

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    © 2015 Abdelraouf et al.Background: There is an urgent need to identify molecular signatures in small cell lung cancer (SCLC) that may select patients who are likely to respond to molecularly targeted therapies. In this study, we investigate the feasibility of undertaking focused molecular analyses on routine diagnostic biopsies in patients with SCLC. Methods: A series of histopathologically confirmed formalin-fixed, paraffin-embedded SCLC specimens were analysed for epidermal growth factor receptors (EGFR), KRAS, NRAS and BRAF mutations, ALK gene rearrangements and MET amplification. EGFR and KRAS mutation testing was evaluated using real time polymerase chain reaction (RT-PCR cobas®), BRAF and NRAS mutations using multiplex PCR and capillary electrophoresis-single strand conformation analysis, and ALK and MET aberrations with fluorescent in situ hybridization. All genetic aberrations detected were validated independently. Results: A total of 105 patients diagnosed with SCLC between July 1990 and September 2006 were included. 60 (57 %) patients had suitable tumour tissue for molecular testing. 25 patients were successfully evaluated for all six pre-defined molecular aberrations. Eleven patients failed all molecular analysis. No mutations in EGFR, KRAS and NRAS were detected, and no ALK gene rearrangements or MET gene amplifications were identified. A V600E substitution in BRAF was detected in a Caucasian male smoker diagnosed with SCLC with squamoid and glandular features. Conclusion: The paucity of patients with sufficient tumour tissue, quality of DNA extracted and low frequency of aberrations detected indicate that alternative molecular characterisation approaches are necessary, such as the use of circulating plasma DNA in patients with SCLC

    Creating diamond color centers for quantum optical applications

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    Nitrogen vacancy (NV) centers in diamond have distinct promise as solid-state qubits. This is because of their large dipole moment, convenient level structure and very long room-temperature coherence times. In general, a combination of ion irradiation and subsequent annealing is used to create the centers, however for the rigorous demands of quantum computing all processes need to be optimized, and decoherence due to the residual damage caused by the implantation process itself must be mitigated. To that end we have studied photoluminescence (PL) from NV−^-, NV0^0 and GR1 centers formed by ion implantation of 2MeV He ions over a wide range of fluences. The sample was annealed at 600∘600^{\circ}C to minimize residual vacancy diffusion, allowing for the concurrent analysis of PL from NV centers and irradiation induced vacancies (GR1). We find non-monotic PL intensities with increasing ion fluence, monotonic increasing PL in NV0^0/NV−^- and GR1/(NV0^0 + NV1^1) ratios, and increasing inhomogeneous broadening of the zero-phonon lines with increasing ion fluence. All these results shed important light on the optimal formation conditions for NV qubits. We apply our findings to an off-resonant photonic quantum memory scheme using vibronic sidebands
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