title: Actinobacteria and cyanobacteria diversity in terrestrial Antarctic microenvironments using culture-dependent and independent methods

authors: Rego, Adriana

subjects: Actinobacteria

abstract: Bacterial diversity from McMurdo Dry Valleys in Antarctica, the largest desert on earth, has become more easily assessed with the development of High Throughput Sequencing (HTS) techniques. However, some of the diversity remains unachievable by the power of sequencing. In this study, we combine cultivation and HTS techniques to survey Actinobacteria and Cyanobacteria diversity along different soil and endolithic micro-environments of Victoria Valley in McMurdo Dry Valleys. Our results have demonstrated that the Dry Valleys Actinobacteria and Cyanobacteria distribution is driven by environmental forces, in particular the effect of water availability and endolithic environments clearly conditioned the distribution of those communities. Data derived from HTS show that the percentage of Cyanobacteria decreases from about 20% in the sample closest to the water source to neglectable values on the last three samples of the transect with less water availability. Inversely, Actinobacteria abundance increases from the wet to the driest samples. Over 30% of the total HTS data set was composed of Actinobacterial strains, mainly distributed by 5 families: Sporichthyaceae, Euzebyaceae, Patulibacteraceae, Nocardioidaceae and Rubrobacteraceae. However, the 11 actinobacterial strains isolated in this study, belonged to Micrococcaceae and Dermacoccaceae families that were underrepresented in the HTS data set. A total of 10 cyanobacterial strains from the order Synechococcales were also isolated, distributed by 4 different genera (Nodosilinea, Leptolyngbya, Pectolyngbya, Acaryochloris). In agreement with the cultivation results, Lepyolyngbya was identified as dominant genera in the HTS data set. Acaryochloris genus were found exclusively in the endolithic sample and represented 44% of the total 16S rDNA sequences, although despite our efforts we were not able to properly isolate any strain from Acaryochloris genus. The importance of combining cultivation and sequencing techniques is highlighted, as we have shown that culture-dependent methods employed in this study were able to retrieve Actinobacteria and Cyanobacteria taxa that were not detected in HTS data set, suggesting that the combination of both strategies can be usefull to recover both abundant and rare members of the communities.

text: Actinobacteria and cyanobacteria diversity in terrestrial Antarctic microenvironments using culture-dependent and independent methods Bacterial diversity from McMurdo Dry Valleys in Antarctica, the largest desert on earth, has become more easily assessed with the development of High Throughput Sequencing (HTS) techniques. However, some of the diversity remains unachievable by the power of sequencing. In this study, we combine cultivation and HTS techniques to survey Actinobacteria and Cyanobacteria diversity along different soil and endolithic micro-environments of Victoria Valley in McMurdo Dry Valleys. Our results have demonstrated that the Dry Valleys Actinobacteria and Cyanobacteria distribution is driven by environmental forces, in particular the effect of water availability and endolithic environments clearly conditioned the distribution of those communities. Data derived from HTS show that the percentage of Cyanobacteria decreases from about 20% in the sample closest to the water source to neglectable values on the last three samples of the transect with less water availability. Inversely, Actinobacteria abundance increases from the wet to the driest samples. Over 30% of the total HTS data set was composed of Actinobacterial strains, mainly distributed by 5 families: Sporichthyaceae, Euzebyaceae, Patulibacteraceae, Nocardioidaceae and Rubrobacteraceae. However, the 11 actinobacterial strains isolated in this study, belonged to Micrococcaceae and Dermacoccaceae families that were underrepresented in the HTS data set. A total of 10 cyanobacterial strains from the order Synechococcales were also isolated, distributed by 4 different genera (Nodosilinea, Leptolyngbya, Pectolyngbya, Acaryochloris). In agreement with the cultivation results, Lepyolyngbya was identified as dominant genera in the HTS data set. Acaryochloris genus were found exclusively in the endolithic sample and represented 44% of the total 16S rDNA sequences, although despite our efforts we were not able to properly isolate any strain from Acaryochloris genus. The importance of combining cultivation and sequencing techniques is highlighted, as we have shown that culture-dependent methods employed in this study were able to retrieve Actinobacteria and Cyanobacteria taxa that were not detected in HTS data set, suggesting that the combination of both strategies can be usefull to recover both abundant and rare members of the communities.

year: 2019

title: Food Preferences of the Brushtail Possum (Trichosurus vulpecula)

authors: Cameron, Kristie Elizabeth

subjects: food preferences

abstract: The common brushtail possum (Trichosurus vulpecula) has been reported to eat vegetation, fruit, invertebrates, and occasionally fungi, eggs and meat. The relative preference between food types found in the wild, however, has not been investigated systematically in a controlled laboratory study. This research investigated captive possums’ food choice using two different methods of preference assessment. The first experiment involved a single stimulus assessment of possums’ (n = 20) consumption of individually presented food items. More than 75% of possums consumed berries, locusts and mushrooms but fewer than 50% of possums consumed fivefinger, raw chicken and eggs. The second experiment that used a paired stimulus assessment to establish relative preference for those foods revealed that no single food was preferred by all possums. Overall locusts were the most preferred food, followed in order of preference by berries, egg, mushrooms, chicken and foliage. The single stimulus preference assessment confirmed the palatability of foods. The paired stimulus assessment provided a rank order of food preferences.

text: Food Preferences of the Brushtail Possum (Trichosurus vulpecula) The common brushtail possum (Trichosurus vulpecula) has been reported to eat vegetation, fruit, invertebrates, and occasionally fungi, eggs and meat. The relative preference between food types found in the wild, however, has not been investigated systematically in a controlled laboratory study. This research investigated captive possums’ food choice using two different methods of preference assessment. The first experiment involved a single stimulus assessment of possums’ (n = 20) consumption of individually presented food items. More than 75% of possums consumed berries, locusts and mushrooms but fewer than 50% of possums consumed fivefinger, raw chicken and eggs. The second experiment that used a paired stimulus assessment to establish relative preference for those foods revealed that no single food was preferred by all possums. Overall locusts were the most preferred food, followed in order of preference by berries, egg, mushrooms, chicken and foliage. The single stimulus preference assessment confirmed the palatability of foods. The paired stimulus assessment provided a rank order of food preferences.

year: 2013

title: Improving prediction of potential for treatment completion at Tai Aroha

authors: Astridge Clarke,  Abigail Darcy

subjects: Treatment

abstract: Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

text: Improving prediction of potential for treatment completion at Tai Aroha Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

year: 2023