45 research outputs found
Charity Fundraising Project:A Team-Based Project for Developing Problem-Structuring Skills
Increasingly, graduates of business schools will face business and organizational situations with a high degree of complexity and ambiguity. In this context, teaching and learning strategies need to develop students’ abilities in problem structuring and complex problem solving. This article describes a team-based project set to teams of four or five students, who are required to design and deliver a fundraising event for their chosen charity. The goal of the fundraising activity is to raise as much money as they can in a 24-hour period. Using ideas from problem-based learning (PBL), students learn frameworks and tools to increase their confidence in these situations. This article describes this activity and will be of interest to teachers of final-year undergraduate and master’s programs looking for a fun and inspiring activity to do with students.Increasingly, graduates of business schools will face business and organizational situations with a high degree of complexity and ambiguity. In this context, teaching and learning strategies need to develop students’ abilities in problem structuring and complex problem solving. This article describes a team-based project set to teams of four or five students, who are required to design and deliver a fundraising event for their chosen charity. The goal of the fundraising activity is to raise as much money as they can in a 24-hour period. Using ideas from problem-based learning (PBL), students learn frameworks and tools to increase their confidence in these situations. This article describes this activity and will be of interest to teachers of final-year undergraduate and master’s programs looking for a fun and inspiring activity to do with students
Towards a simple global-standard bioassay for a key ecosystem process: organic-matter decomposition using cotton strips
Cotton-strip bioassays are increasingly used to assess ecosystem integrity because they provide a standardized measure of organic-matter decomposition – a fundamental ecosystem process. However, several different cotton- strip assays are routinely used, complicating the interpretation of results across studies, and hindering broader synthesis. Here, we compare the decay rates and assemblages of bacteria and fungi colonizing the three most commonly used cotton materials: Artist’s canvas, Calico cloth, and Empa fabric. Cotton strips from each material type were incubated in 10 streams that span a wide range of physicochemical properties across five ecoregions. Additionally, to evaluate responses to environmental stress without potentially confounding biogeographical effects, we deployed identical bioassays in five streams across an acidification gradient within a single ecoregion. Across all streams decomposition rates (as tensile strength loss [TSL]) differed among the three cotton ma- terials; Calico cloth decomposed fastest (time to 50% TSL [T50]=16.7d), followed by the Empa fabric (T50 = 18.3 d) and then Artist’s canvas (T50 = 21.4 d). Despite these differences, rates of TSL of the three cotton materials responded consistently to variation in environmental conditions; TSL of each fabric increased with stream temperature, dissolved-nutrient concentrations and acid-neutralizing capacity, although Artist’s canvas and Calico cloth were more sensitive than Empa fabric. Microbial communities were similar among the mate- rials, and values of community structure (e.g., phylotype richness and diversity) were comparable to those reported for decaying leaves in streams from the same region, the major natural basal carbon resource in forested-stream ecosystems. We present linear calibrations among pairs of assays so that past and future studies can be expressed in a “common currency” (e.g., Artist’s-fabric equivalents) ‘past and future studies’ repeated two times in the sentence. Lastly, given its relatively low within-site variability, and the large number of streams where it has been used (> 700 across the globe), we recommend Artist’s fabric for future work. These results show that cotton provides an effective and realistic standardized substrate for studying heterotrophic microbial assemblages, and acts as a reasonable proxy for more chemically complex forms of detritus. These findings add to growing evidence that cotton-strip bioassays are simple, effective and easily standardized indicators of het- erotrophic microbial activity and the ecosystem processes that result
Identifying A National Leadership Skills Training And Development Strategy For Leaders Within Sector Education Training Authorities (SETAS)
Through a literature survey and a qualitative survey of the views of a selected sample of key role-players in the implementation of the South African Skills Development Strategy a number of transformational leadership competencies were identified that influence the effectiveness of Sector Education and Training Authorities (SETAs). A subsequent quantitative survey of the views of a random sample of SETA managers and Board members ranked the identified leadership competencies in terms of relevance to and importance for effectiveness of SETA leadership teams. The research results were applied to propose a learning programme strategy to develop the identified transformational leadership competencies amongst SETA leaders
Probiotics in aquaculture: The need, principles and mechanisms of action and screening processes
Aquaculture production of molluscs is worth US$11 billion per year and represents 65% of World mollusc product. A significant limitation to the industry is loss of stock through bacterial disease. Traditional methods to combat disease with antibiotics have been questioned and alternatives have been sought. The field of probiotics as well as the screening methods used to acquire probiotic strains for the alternative management of disease in aquaculture is discussed. This review provides a comprehensive summary of probiotics in aquaculture with special reference to mollusc culture. © 2007 Elsevier B.V. All rights reserved
Identifying A National Leadership Skills Training And Development Strategy For Leaders Within Sector Education Training Authorities (SETAS)
Two pathogens of greenshell™ mussel larvae, perna canaliculus: Vibrio splendidus and a V. coralliilyticus/neptunius-like isolate
Bacterial pathogens of Greenshell™ mussel (GSM) larvae can cause batch losses during hatchery production. Twenty-two isolates were screened using a larval bioassay. Two strains were identified as potential pathogens. Phenotypic identification of these strains revealed two non-reactive Gram-negative, oxidase positive rods. Sequencing of the 16S rRNA gene identified Vibrio splendidus and a V. coralliilyticus/neptunius-like isolate as pathogens of GSM larvae, with an ability to cause 83% and 75% larval mortality in vitro, respectively, at a concentration of 102 CFU mL-1. Histopathology indicated that the route of infection was via the digestive system. Using healthy larvae as target hosts, Koch's postulates were confirmed for the two isolates. This is the first report on pathogens of GSM larvae. © 2009 Blackwell Publishing Ltd
Alteromonas macleodii 0444 and Neptunomonas sp. 0536, two novel probiotics for hatchery-reared Greenshell™ mussel larvae, Perna canaliculus
Antibiotic management of aquacultured animals, such as Greenshell™ mussel (GSM) larvae, Perna canaliculus, is undesirable because of health concerns and political pressures; hence, alternatives are needed. Herein, two novel probiotic bacteria were identified and trialled in a GSM larval rearing hatchery. Sequencing of the 16S rRNA gene and phylogenetic analysis identified the strains as Alteromonas macleodii 0444 and Neptunomonas sp. 0536. Both probiotics were evaluated separately at the Glenhaven Aquaculture Centre hatchery facility during routine larval rearing and when the larvae were challenged with both a high (107 and 106CFUml-1) and low (106 and 105CFUml-1) pathogenic dose of Vibrio sp. DO1 and V. splendidus respectively. In all experiments, probiotic application improved larval survival significantly when administered prior to pathogen exposure. Across all experiments, larvae that were exposed to the high and low dosages of pathogens averaged 14% and 36% survival respectively on the fourth day following pathogen exposure. The administration of probiotics prior to pathogen challenge resulted in larval survival of 50% and 66% respectively. Non-inoculated control larvae and larvae administered the probiotic alone demonstrated 67% and 79% survival respectively. Neptunomonas sp. 0536 appeared to suppress naturally occurring vibrios in the culture environment of healthy GSM larvae. This is the first report of A. macleodii and Neptunomonas sp. as probiotic bacteria in a large scale production facility. © 2010 Elsevier B.V
Performance of single and multi-strain probiotics during hatchery production of Greenshell <sup>™</sup> mussel larvae, Perna canaliculus
Earlier work identified two novel strains of probiotic bacteria, Alteromonas macleodii 0444 and Neptunomonas sp. 0536, for Greenshell ™ mussel (Perna canaliculus) larvae. Herein, we investigated whether the combination of the two probiotics in a multi-strain mix provided a) enhanced larval production during routine rearing and b) improved larval protection during two separate pathogen-challenge tests (Vibrio sp. DO1 and Vibrio splendidus). The response of larvae to multi-strain or single-strain probiotic administration was compared to that of larvae without probiotics. Two concentrations of each probiotic were tested (10 7 and 10 8CFUml -1). Addition of 10 8CFUml -1 multi-strain mix in the routine rearing of larvae yielded smaller-sized larvae and a lower feeding rate when compared with the 10 7CFUml -1 and control groups. During the challenge test against Vibrio sp. DO1 and V. splendidus, protection by single-strain probiotic administration was observed at both levels of probiotic administration (10 7 and 10 8CFUml -1), with no apparent added protection from multi-strain probiotics. Although 10 8CFUml -1 levels provided protection against pathogen attack, they were also potentially detrimental to normal larval rearing when administered in combination and, as such, where administration of A. macleodii 0444 and Neptunomonas sp. 0536 would be applied together, a multi-strain mix of probiotics at 10 7CFUml -1, is recommended as the best concentration of each probiotic. © 2012 Elsevier B.V
Screening for probiotics of Greenshell™ mussel larvae, Perna canaliculus, using a larval challenge bioassay
A bioassay was developed to screen and select bacterial strains as probiotics for an alternative to antibiotic usage in the management of bacterial pathogens of Greenshell™ mussel (GSM) larvae, Perna canaliculus. Sixty-nine isolates originating from a GSM hatchery environment were tested for probiotic activity in larval pathogen-challenge bioassays conducted in tissue culture dishes (TCDs). Vibrio splendidus and a V. coralliilyticus/neptunius-like isolate, Vibrio sp. DO1, were the tested pathogens. Forty of the tested isolates afforded larval survival significantly greater than pathogen controls (p < 0.05). The bioassay technique achieved a 58% success rate in searching for putative probiotics and highlighted the benefit of including the host animal in the first stage of the screening procedure. The time of inoculation of putative probiotic strains prior to pathogen challenge influenced the outcome of the assay. A pre-exposure period of 20 h revealed a greater number of potential probiotics than a two-hour pre-exposure period. Pilot challenge tests, under normal hatchery conditions, confirmed the usefulness of the TCD screening method in recognising effective probiotics. © 2009 Elsevier B.V. All rights reserved
Challenge of New Zealand Greenshell™ mussel Perna canaliculus larvae using two Vibrio pathogens: A hatchery study
Bacterial diseases ra large problem in aquaculture hatcheries. The successful design and implementation of protective measures in the hatchery depends on an understanding of the dynamics of the infection process. Developing an in situ experimental protocol for pathogen challenge is therefore of paramount importance. Here, we demonstrated the minimum effective pathogenic dose (MEPD) of Vibrio splendidus (105 CFU ml-1) and a Vibrio coralliilyticus/neptunius-like isolate, Vibrio sp. DO1 (106 CFU ml-1), for New Zealand Greenshell™ mussel (GSM, Perna canaliculus) larvae during hatchery production. In a flow-through water hatchery system, larvae given 1 to 2 h of static water exposure to these pathogen doses showed respective average cumulative mortalities of 58 and 69% on the fourth day following pathogen exposure. After the 1 to 2 h static exposure, larvae were returned to flow-through water. Larvae exposed to a dosage one order of magnitude greater than the MEPD had higher mortalities of 73 and 96% for V. splendidus and Vibrio sp. DO1 respectively. These 4 levels of mortality were significantly greater than those of the non-exposed control larvae which respectively averaged 23 and 35% in experiments involving V. splendidus and Vibrio sp. DO1. Experiments were repeated 4 times to confirm reproducibility. After pathogen exposure, pathogens were detected in the larvae and tank water of treatments with dosages of ≥ 105 CFU ml-5 (V. splendidus) and 106 CFU ml-1 (Vibrio sp. DO1), but not in treatments with lower pathogen dosages. The challenge protocols are reproducible and provide an opportunity to assess measures for the protection of GSM larvae against infection in the hatchery environment. © Inter-Research 2009