Photosynthesis in Silico: A multimedia CD-ROM combining animations, simulations and self-paced modules for photosynthesis education at all tertiary levels

Photosynthesis is a vital component of any undergraduate biology course. Despite its central importance in providing biochemical energy, fixed carbon and oxygen for all life on Earth, it remains an area which students find uninteresting and difficult to comprehend. This difficulty is compounded by problems with laboratory equipment for practical classes, which tends to be either expensive and complex, or simple and unreliable, making it extremely difficult to provide effective, hands-on teaching of photosynthesis to the large class sizes in undergraduate biology courses. A set of interactive, multimedia modules have been combined on a CD-ROM, which provides a new approach to university teaching of photosynthesis. Features include animations of the photosynthetic electron transport process, serving both as an introduction to experimental exercises and as stand-alone material for use in undergraduate lectures or tutorials, and simulated experimental models of photosynthetic gas exchange and chlorophyll fluorescence which can be used either as stand-alone packages or, where equipment is available, to supplement and enrich a laboratory demonstration/experiment. These provide students with access to the latest experimental techniques and theory, providing an experience and knowledge base that facilitates understanding of the subject in greater depth

Antarctica\u27s \u27moss forests\u27 are drying and dying

The lush moss beds that grow near East Antarctica\u27s coast are among the only plants that can withstand life on the frozen continent. But our new research shows that these slow-growing plants are changing at a far faster rate than anticipated

Desiccation protects Antarctic mosses from ultraviolet-B induced DNA damage

Antarctic mosses live in a frozen desert, and are characterised by the ability to survive desiccation. They can tolerate multiple desiccation-rehydration events over the summer growing season. As a result of recent ozone depletion, such mosses may also be exposed to ultraviolet-B radiation while desiccated. The ultraviolet-B susceptibility of Antarctic moss species was examined in a laboratory experiment that tested whether desiccated or hydrated mosses accumulated more DNA damage under enhanced ultraviolet-B radiation. Accumulation of cyclobutane pyrimidine dimers and pyrimidine (64) pyrimidone dimers was measured in moss samples collected from the field and then exposed to ultraviolet-B radiation in either a desiccated or hydrated state. Two cosmopolitan species, Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., B.Mey. and Scherb, were protected from DNA damage when desiccated, with accumulation of cyclobutane pyrimidine dimers reduced by at least 60% relative to hydrated moss. The endemic Schistidium antarctici (Cardot) L.I. Savicz and Smirnova accumulated more DNA damage than the other species and desiccation was not protective in this species. The cosmopolitan species remarkable ability to tolerate high ultraviolet-B exposure, especially in the desiccated state, suggests they may be better able to tolerate continued elevated ultraviolet-B radiation than the endemic species

Stress in native grasses under ecologically relevant heat waves

Future increases in the intensity of heat waves (high heat and low water availability) are predicted to be one of the most significant impacts on organisms. Using six native grasses from Eastern Australia, we assessed their capacity to tolerate heat waves with low water availability. We were interested in understanding differential response between native grasses of differing photosynthetic pathways in terms of physiological and some molecular parameters to ecologically relevant summer heat waves that are associated with low rainfall. We used a simulation heatwave event in controlled temperature cabinets and investigated effects of the different treatments on four stress indicators: leaf senescence, leaf water content, photosynthetic efficiency and the relative expression of two heat shock proteins, Hsp70 and smHsp17.6. Leaf senescence was significantly greater under the combined stress treatment, while declines in leaf water content and photosynthetic efficiency were much larger for C3 than C4 plants, particularly under the combined stress treatment. Species showed an increase in expression of Hsp70 associated with heat treatment, rather than drought stress. In contrast Hsp17.6 was only detected in two species, responding to heat rather than drought, although species\u27 responses were variable. Overall, the C3 species were less tolerant than C4 species. Variation in individual plants within species was evident, especially under multiple stresses, and indicates that losses of individual plants may occur during a heat wave associated with this variability in tolerance. Heat waves will impose significant stress on plant communities that would not otherwise occur when heat and drought stress are experienced singly. Using ecologically relevant heat stress is likely to yield better predictability of how native plants will cope under a hotter, drier future

Facilitation, competition and parasitic facilitation amongst invasive and native liana seedlings and a native tree seedling

Lianas are prevalent in gaps and edges of forests where they compete intensely with trees, reducing growth and recruitment. Invasive lianas have the potential to be particularly harmful as the competitive advantage of the liana life history may be coupled with the more competitive qualities of invasiveness. However, in early stages of growth of lianas and native tree seedlings, facilitatory interactions or competitive interactions associated with soil nutrients may be more prevalent. We investigated interactions at the early stages of growth between native and invasive lianas with a common rainforest tree of temperate Australian rainforests under different light conditions. Invasive lianas, as a group, were not more competitive than native lianas in reducing growth of a native rainforest seedling. At this stage in the life cycle most lianas were as competitive as a conspecific seedling. However, one invasive liana, Anredera cordifolia, was particularly competitive and reduced biomass of tree seedlings. Light had little effect on growth of lianas nor on the impact of competition, however, specific leaf area differed between low and medium light conditions. Moderate light did improve growth in the rainforest tree seedling. When lianas were grown with a rainforest tree, three liana species overyielded, while one species was unaffected by growing with the tree seedling. Overyielding suggests a strong positive interaction with the neighbouring plant, mediated through belowground processes. We discuss the potential for these interactions to be facilitative, parasitic or competitive. We therefore show that interactions early in the life of rainforest species can be complex mixtures of interactions which are likely to influence the ability of lianas to dominate rainforests

The Black Church : responding to the drug-related mass incarceration of young Black males : If you had been here my Brother would not have died!

The mass incarceration of young Black males for drug-related offences is a social issue that has broad implications. Some scholars have described this as a new form of racism that needs to be addressed through the concerted effort of various institutions, including the Black Church. In this paper the authors will elucidate the past and current roles of the Black Church, discuss the utilization of the social work Theory of Empowerment and Black Church theology to address the disproportionality of drug-related mass incarceration of young Black males, focus on initiatives undertaken by the Black Church to address this issue and further, discuss the role of the Black Church in ex-drug offender reentry and reintegration. This paper will conclude with implications for the Black Church and incarcerated young Black males

Photosynthesis in Silico: A multimedia CD-ROM combining animations, simulations and self-paced modules for photosynthesis education at all tertiary levels

Photosynthesis is a vital component of any undergraduate biology course. Despite its central importance in providing biochemical energy, fixed carbon and oxygen for all life on Earth, it remains an area which students find uninteresting and difficult to comprehend. This difficulty is compounded by problems with laboratory equipment for practical classes, which tends to be either expensive and complex, or simple and unreliable, making it extremely difficult to provide effective, hands-on teaching of photosynthesis to the large class sizes in undergraduate biology courses. A set of interactive, multimedia modules have been combined on a CD-ROM, which provides a new approach to university teaching of photosynthesis. Features include animations of the photosynthetic electron transport process, serving both as an introduction to experimental exercises and as stand-alone material for use in undergraduate lectures or tutorials, and simulated experimental models of photosynthetic gas exchange and chlorophyll fluorescence which can be used either as stand-alone packages or, where equipment is available, to supplement and enrich a laboratory demonstration/experiment. These provide students with access to the latest experimental techniques and theory, providing an experience and knowledge base that facilitates understanding of the subject in greater depth

Dominating the Antarctic environment: bryophytes in a time of change

Polar ecosystems, and particularly Antarctica, are one of the few environs in which bryophytes dominate the flora. Their success in these regions is due to bryophytes’ ability to withstand an array of harsh conditions through their poikilohydric lifestyle. However, the unique conditions that allow bryophytes to proliferate over other forms of vegetation also create considerable limitations to growth and photosynthetic activity. High latitude areas are already experiencing some of the most pronounced and rapid climatic change, especially in the Arctic, the Sub-Antarctic Islands and Maritime Antarctica, and these are predicted to continue over the next century. This climatic change is already impacting the flora of the polar regions both via direct and/or indirect impacts on plant species. Water availability and temperature are undoubtedly the most influential factors that determine bryophyte productivity in the Antarctic, but the ozone hole is also having an impact either directly via increased ultraviolet-B radiation and/or indirectly through the increasing wind speeds associated with ozone depletion. In a time of shifting climate the dominance of bryophytes in these regions may be threatened

Assessment of Antarctic moss health from multi-sensor UAS imagery with Random Forest Modelling

Moss beds are one of very few terrestrial vegetation types that can be found on the Antarctic continent and as such mapping their extent and monitoring their health is important to environmental managers. Across Antarctica, moss beds are experiencing changes in health as their environment changes. As Antarctic moss beds are spatially fragmented with relatively small extent they require very high resolution remotely sensed imagery to monitor their distribution and dynamics. This study demonstrates that multi-sensor imagery collected by an Unmanned Aircraft System (UAS) provides a novel data source for assessment of moss health. In this study, we train a Random Forest Regression Model (RFM) with long-term field quadrats at a study site in the Windmill Islands, East Antarctica and apply it to UAS RGB and 6-band multispectral imagery, derived vegetation indices, 3D topographic data, and thermal imagery to predict moss health. Our results suggest that moss health, expressed as a percentage between 0 and 100% healthy, can be estimated with a root mean squared error (RMSE) between 7 and 12%. The RFM also quantifies the importance of input variables for moss health estimation showing the multispectral sensor data was important for accurate health prediction, such information being essential for planning future field investigations. The RFM was applied to the entire moss bed, providing an extrapolation of the health assessment across a larger spatial area. With further validation the resulting maps could be used for change detection of moss health across multiple sites and seasons