Evaluation of Efficacy of New and Existing Desiccants in Lentil (Lens culinaris Medik)

In western Canada, weeds resistant to acetolactate synthase (ALS) inhibitors have created an extensive challenge for many lentil (Lens culinaris L.) producers, particularly producers growing imidazolinone (IMI) resistant lentil. These resistant weed biotypes may not always impact the yield of the current lentil crop, but the resulting seedbank additions and subsequent spread of these resistant biotypes can have a long-lasting impact in successive growing seasons. An effective weed seedbank management program is important to reduce the impact of problem weeds and is vital for farming operations to remain profitable and sustainable in future seasons. This 3-year study at Saskatoon and Scott, Saskatchewan (2012-2014) evaluated the impact of several pre-harvest herbicides on juncea canola (Brassica juncea L.) and kochia (Kochia scoparia L.) dry-down, weed seed production, and the viability and vigour of the weed seeds. The field study examined the effects of different contact herbicides, tank mixed with two different rates of glyphosate (450 g a.i. ha-1 and 900 g a.i. ha-1), on weed dry-down, weed seed production and the viability and vigour of developing weed seeds. Five contact herbicides were evaluated: pyraflufen, flumioxazin, saflufenacil, glufosinate, and diquat. Diquat (415 g a.i. g ha-1) and glufosinate (600 g a.i. ha-1) applied alone or tank mixed with glyphosate provided greater dry-down of kochia and juncea compared to flumioxazin, pyraflufen, and saflufenacil. No herbicide treatment was able to significantly reduce seed production of either weed species. Although several treatments reduced the thousand seed weight (TSW) of kochia, only a high rate of glyphosate was effective at reducing juncea TSW. Growth cabinet studies showed that glyphosate and glufosinate applied alone or in a tank mix together significantly reduced kochia seedling vigour. The number of viable juncea seeds was reduced significantly when glyphosate or diquat was applied alone. Overall, glyphosate applied alone was just as effective at reducing seed germination and seedling vigour as tank-mixes with diquat or glufosinate. However, a tank mix of glufosinate and glyphosate as a pre-harvest herbicide treatment in lentil would be the best option to delay the development of glyphosate resistance in kochia and wild mustard. This tank mix would also reduce the viability and vigour of kochia seed additions into the seedbank, as well as provide plant dry-down of lentil and weedy material prior to harvest.

Weed seedbank management and the infuence of seed predators

Non-Peer ReviewedIncreasing herbicide resistance has led weed scientists to focus on managing the weed seedbank. Indeed, seedbank management is critical and should be a priority for annual weeds. Post-emergence weed control should be seen as a rescue treatment and not as a first line of defence. But which weeds do we prioritize and what tactics can we use to manage the seedbank? This talk will shed light on weed species of priority for seedbank management, criteria to implement for managing the seedbank, and novel methods of seedbank management with a major emphasis on seed predators. Regardless of how producers try to manage weed seed shed, seeds will fall to the ground and thus we must develop ways to manage these seeds. Seed predators represent a major opportunity to help exhaust weed seeds from the seedbank

Design and feasibility testing of a novel group intervention for young women who binge drink in groups

BackgroundYoung women frequently drink alcohol in groups and binge drinking within these natural drinking groups is common. This study describes the design of a theoretically and empirically based group intervention to reduce binge drinking among young women. It also evaluates their engagement with the intervention and the acceptability of the study methods.MethodsFriendship groups of women aged 18–35 years, who had two or more episodes of binge drinking (>6 UK units on one occasion; 48g of alcohol) in the previous 30 days, were recruited from the community. A face-to-face group intervention, based on the Health Action Process Approach, was delivered over three sessions. Components of the intervention were woven around fun activities, such as making alcohol free cocktails. Women were followed up four months after the intervention was delivered. Results The target of 24 groups (comprising 97 women) was recruited. The common pattern of drinking was infrequent, heavy drinking (mean consumption on the heaviest drinking day was UK 18.1 units). Process evaluation revealed that the intervention was delivered with high fidelity and acceptability of the study methods was high. The women engaged positively with intervention components and made group decisions about cutting down. Twenty two groups set goals to reduce their drinking, and these were translated into action plans. Retention of individuals at follow up was 87%.ConclusionsThis study successfully recruited groups of young women whose patterns of drinking place them at high risk of acute harm. This novel approach to delivering an alcohol intervention has potential to reduce binge drinking among young women. The high levels of engagement with key steps in the behavior change process suggests that the group intervention should be tested in a full randomised controlled trial

An innovative pseudotypes-based Enzyme-Linked Lectin Assay for the measurement of functional anti-neuraminidase antibodies

Antibodies (Ab) to neuraminidase (NA) play a role in limiting influenza infection and might help reduce the disease impact. The most widely used serological assay to measure functional anti-NA immune responses is the Enzyme-Linked Lectin Assay (ELLA) which relies on hemagglutinin (HA) mismatched virus reassortants, or detergent treated viruses as the NA source to overcome interference associated with steric hindrance of anti-HA Ab present in sera. The difficulty in producing and handling these reagents, which are not easily adapted for screening large numbers of samples, limits the routine analysis of functional anti-NA Ab in clinical trials. In this study, we produced influenza lentiviral pseudoparticles (PPs) containing only the NA antigen (NA-PPs) with a simple two-plasmid co-transfection system. NA-PPs were characterized and tested as an innovative source of NA in the NA inhibition (NI) assay. Both swine A/California/07/2009 (H1N1) and avian A/Turkey/Turkey/01/2005 (H5N1) N1s within NA-PPs retained their sialidase activity and were specifically inhibited by homologous and N1 subtype-specific, heterologous sheep sera. Moreover, A/California/07/2009 N1-PPs were a better source of NA compared to whole live and detergent treated H1N1 viruses in ELLA, likely due to lack of interference by anti-HA Ab, and absence of possible structural modifications caused by treatment with detergent. This innovative assay is safer and applicable to all NAs. Taken together, these results highlight the potential of NA-PPs-based NI assays to be developed as sensitive, flexible, easy to handle and scalable serological tests for routine NA immune response analysis

Expression and Characterization of Recombinant, Tetrameric and Enzymatically Active Influenza Neuraminidase for the Setup of an Enzyme-Linked Lectin-Based Assay

<div><p>Developing a universal influenza vaccine that induces broad spectrum and longer-term immunity has become an important potentially achievable target in influenza vaccine research and development. Hemagglutinin (HA) and neuraminidase (NA) are the two major influenza virus antigens. Although antibody responses against influenza virus are mainly directed toward HA, NA is reported to be more genetically stable; hence NA-based vaccines have the potential to be effective for longer time periods. NA-specific immunity has been shown to limit the spread of influenza virus, thus reducing disease symptoms and providing cross-protection against heterosubtypic viruses in mouse challenge experiments.</p><p>The production of large quantities of highly pure and stable NA could be beneficial for the development of new antivirals, subunit-based vaccines, and novel diagnostic tools. In this study, recombinant NA (rNA) was produced in mammalian cells at high levels from both swine A/California/07/2009 (H1N1) and avian A/turkey/Turkey/01/2005 (H5N1) influenza viruses. Biochemical, structural, and immunological characterizations revealed that the soluble rNAs produced are tetrameric, enzymatically active and immunogenic, and finally they represent good alternatives to conventionally used sources of NA in the Enzyme-Linked Lectin Assay (ELLA).</p></div

Titration of NA activity and its specific inhibition by ELLA.

<p>(A) NA activity in A/CA and A/tk/TK N1-PPs, and Mock samples was titrated incubating fetuin-coated plates with serial dilutions of the culture supernatants. A NA working dilution corresponding to the beginning of the linear part of the titration curve (OD_450nm = 2) was selected to standardize NA activity in the inhibition test. Each data point represents the mean and the standard deviation from at least two independent experiments. Non-parametric Mann-Whitney test was performed to compare ODs values at each PPs dilution; *** p < 0.001, ** p < 0.005, and * p < 0.05. (B) Inhibition of A/CA and A/tk/TK N1-PPs enzymatic activity by sera specific for N1 (A/California/07/2009, A/turkey/Turkey/01/2005, A/NewCaledonia/20/99), N2 (A/Wyoming/3/2003) and B (B/Malaysia/2506/2004 and B/Florida/4/2006) NAs. Each bar represents the mean and the standard deviation from at least two independent experiments.</p

NI titers measured in a panel of sera using different sources N1 from A/California/07/2009 (H1N1) virus.

<p>(A) Sheep polyclonal anti-N1 A/California/07/2009 and anti-NA B/Florida/04/2006 sera, (B) mouse polyclonal anti-HA sera with low and high HI titers, and (C) mouse polyclonal preimmune and anti-A/California/07/2009 subunit vaccine sera and normal human serum were tested <i>vs</i> the whole live and Triton X-100 treated A/California/07/2009 (H1N1) viruses and <i>vs</i> N1-PPs, with or without the mismatched HA from A/Vietnam/1194/04 (H5N1) influenza virus. Each bar represents the mean and the standard deviation from at least two independent experiments. Parametric One-Way ANOVA test was performed to compare NI titers; *** p < 0.001, ** p < 0.005, and * p < 0.05.</p

Transmission electron microscopy analysis of N1-PPs.

<p>Culture supernatants of 293T cells transfected with no DNA (Mock) and with both pNL4-3luc and pI.18_ N1 from the A/turkey/Turkey/01/2005 influenza strain (A/tk/TK N1-PPs) plasmids, 48 h post-transfection. Negative staining of A/tk/TK N1-PPs (A) and Mock (B), and immunogold labeling of NA in A/tk/TK N1-PPs (C) and Mock (D) samples with mouse polyclonal anti-N1 A/turkey/Turkey/01/2005 serum. Arrows represent gold-labeled Ab bound to NA. Scale bar is 200 nm.</p

Detection of NA, p24 and p17 proteins in A/tk/TK N1-PPs.

<p>Culture supernatants of 293T cells transfected without plasmids (Mock) and with different combinations of the two plasmids (ΔN1-PPs or pI.18_N1) were resolved by 4–12% SDS-PAGE in reducing conditions, transferred to nitrocellulose membrane and immunoblotted with (A) sheep polyclonal anti-N1 A/Turkey, (B) mouse monoclonal anti-p24 and, (C) rabbit polyclonal anti-p55+p17 Ab. Arrows identify the corresponding protein. Data shown are representative of two independent experiments.</p

rNAs as sources of sialidase in ELLA.

<p>(A) NI titers determined in a panel of NIBSC sheep polyclonal sera specific for A/turkey/Turkey/01/2005, A/California/07/2009 and A/Caledonia/22/99 N1, A/Wyoming/3/2003 N2, and B/Malaysia/2506/2004 and B/Florida/4/2006 B NAs. (B) NI titers in sera of mice immunized with swine H1N1 and avian H5N1 rNAs adjuvanted with MF59. Data show mean±SD from three independent experiments performed in duplicate. NA = not assayed.</p