Preliminary Evaluation of a Dodder Anthracnose Fungus from China as a Mycoherbicide for Dodder Control in the US

Dodder (Cuscuta spp.) is a noxious, parasitic, annual weed throughout most of the United States. A fungus used to control it in China was imported under permit for studies with U.S. dodder species in containment. The fungus, Colletotrichum gloeosporioides, sporulated on liquid and solid media at room temperature. Conidia from 7-12 day old cultures were diluted to 3.5 to 7 X 16⁶ spores ml^-1 for host range inoculations. Germination on water agar at 24 hrs was higher at 28 than 30 or 24 C. Inoculated plants were exposed to dew periods of 12-1 4 hrs at 24 or 28 C, then transferred to growth chambers with 1 2-hr photoperiods at constant temperatures of 24, 28, and 32C. Dodder species were severely diseased but rarely killed. Symptoms were most severe on native collections of Cuscuta campestris after 4 to 5 days incubation when this species on periwinkle seedlings was inoculated with 3.5 to 7 X 10⁵ spores ml^-1 . Cuscuta cuspidata, C. pentagona, and C. campestris from a California seedlot were also tested under optimum conditions for disease. The C. campestris from California was the most susceptible. Inoculation of 16 species in eight plant families revealed no other host except sweet potato which developed a necrotic fleck. This research indicates a need for strain improvement prior to field tests

Contribution of the antibiotic chloramphenicol and its analogues as precursors of dichloroacetamide and other disinfection byproducts in drinking water

Dichloroacetamide (DCAcAm), a disinfection byproduct, has been detected in drinking water. Previous research showed that amino acids may be DCAcAm precursors. However, other precursors may be present. This study explored the contribution of the antibiotic chloramphenicol (CAP) and two of its analogues (thiamphenicol, TAP; florfenicol, FF) (referred to collectively as CAPs), which occur in wastewater-impacted source waters, to the formation of DCAcAm. Their formation yields were compared to free and combined amino acids, and they were investigated in filtered waters from drinking-water-treatment plants, heavily wastewater-impacted natural waters, and secondary effluents from wastewater treatment plants. CAPs had greater DCAcAm formation potential than two representative amino acid precursors. However, in drinking waters with ng/L levels of CAPs, they will not contribute as much to DCAcAm formation as the μg/L levels of amino acids. Also, the effect of advanced oxidation processes (AOPs) on DCAcAm formation from CAPs in real water samples during subsequent chlorination was evaluated. Preoxidation of CAPs with AOPs reduced the formation of DCAcAm during postchlorination. The results of this study suggest that CAPs should be considered as possible precursors of DCAcAm, especially in heavily wastewater-impacted waters

Aerobic Rice - responding to water scarcity, An impact assessment of the ‘STAR in Asia’ project

Rice, a staple food for over 70% of Asians, is also the single biggest user of water, requiring 2-3 times more input (irrigation plus rain) water per unit of grain produced than crops such as wheat and maize. With growing populations, increased urbanisation and environmental degradation, the supply of fresh water is depleting. Recognising the water constraints to rice yield, the aim of the project entitled ‘Developing a System of Temperate and Tropical Aerobic Rice (STAR) in Asia’ was to develop water-efficient aerobic rice technologies. This paper highlights the success of that project

Financial education and asset allocation

We conduct a clinical study on a firm that restructures its 401(k) plan and simultaneously offers financial education seminars to its employees. The restructuring requires each employee to restate allocation percentages, thus we are able to analyze the specific benefits of retirement planning seminars on the asset allocation decision. We find that seminar attendance is associated with increased portfolio diversification and improved risk management. When combined with changes in return, the overall result is that seminar attendees create more efficient portfolios, which implies a better understanding of the retirement planning process

Book Reviews

Teaching/Communication/Extension/Profession,

A comparative study of how British tits encode predator threat in their mobbing calls

This research funded by NERC (NE/J018694/1), the Royal Society (RG2012R2), the M. J. Murdock Charitable Trust (2014199) and the University of St Andrews (University of St Andrews 600th Year Scholarship and the St Leonard's Fee Scholarship).Many species use antipredator vocalizations to signal information about potential predators, including the level of threat posed by a particular predator. It is not clear, however, why only some prey species do this. Because they use multiple mechanisms to encode threat-specific information about predators, North American Paridae species have been a particularly useful model for studying antipredator signals. Paridae as a group are also useful for examining phylogenetic conservation of vocal signals because all of these species (at least those studied previously) employ similar ways of encoding information about predator threat. To test whether the ways in which predator threat information is encoded (here measured by a bird's vocal output) are conserved across a family with similar vocalizations, we used taxidermy mounts to simulate low- and high-threat predators to induce mobbing in six species across five genera of British Paridae. We found that, like North American species, British tits all increased their call rate in response to predators compared with nonthreatening control mounts, but they all varied in the number and types of additional ways they encoded this information. Some species (blue and willow tits) used all four ways to differentiate between different threat predators, while others used only two (crested tits), one (great and coal tits) or none at all (willow tits). The variation in the way each species encoded predator threat information in their calls was not explained by phylogenetic relatedness or by variation in life history. To better understand patterns of information encoding across related species, we suggest that playback experiments to determine how encoded information is used by conspecifics and heterospecifics might provide insights about why some species encode information about predator threat in multiple ways.PostprintPeer reviewe

Hoo are you? Tits do not respond to novel predators as threats

The Natural Environment Research Council (NE/J018694/1), the Royal Society (RG2012R2), the M. J. Murdock Charitable Trust (2014199) and the University of St Andrews (University of St Andrews 600th Year Scholarship and the St Leonard’s Fee Scholarship) provided funding.To combat the threat of predation, prey species have developed a variety of ways to recognize and respond appropriately to novel predators. While there is evidence that predator recognition does not require learning in certain species, learning appears to play an important role for other species. In systems where learning is important, it is less clear whether predator identification requires prior experience with specific predators or, whether general experience with predators provides sufficient tools for identifying similar species of novel predators. Here we test whether wild-living adult birds recognize a dangerous predator that occurs in only part of their geographical range. We presented taxidermy mounts of little owls, Athene noctua, and sparrowhawks, Accipiter nisus, to blue tits, Cyanistes caeruleus, and great tits, Parus major. All populations of both tit species co-occur with sparrowhawks, but populations differ in their prior experience with little owls. We found that tits that overlap geographically with little owls responded to little owls using the same intensity of mobbing behaviour exhibited toward sparrowhawks. In populations with no historical contact with little owls, however, both blue and great tits treated little owls as a lower threat than sparrowhawks. These results suggest that blue tits and great tits do not generalize ‘predatory features’ to novel predators and instead need prior experience with specific predators before they assign the correct level of threat.Publisher PDFPeer reviewe

Core disgust is attenuated by ingroup relations

We present the first experimental evidence to our knowledge that ingroup relations attenuate core disgust and that this helps explain the ability of groups to coact. In study 1, 45 student participants smelled a sweaty t-shirt bearing the logo of another university, with either their student identity (ingroup condition), their specific university identity (outgroup condition), or their personal identity (interpersonal condition) made salient. Self-reported disgust was lower in the ingroup condition than in the other conditions, and disgust mediated the relationship between condition and willingness to interact with target. In study 2, 90 student participants smelled a sweaty target t-shirt bearing either the logo of their own university, another university, or no logo, with either their student identity or their specific university identity made salient. Walking time to wash hands and pumps of soap indicated that disgust was lower where the relationship between participant and target was ingroup rather than outgroup or ambivalent (no logo)

Asset Allocation for Retirement: Simple Heuristics and Target-Date Funds

We examine common asset allocation strategies for retirement investing, considering both static and dynamic approaches, as well as those allocation policies used by leading target-date fund providers. We studied the average performance of each strategy over historical rolling periods (that is, bootstrapping), using actual annual returns starting in 1926. Then we applied the simulation method to review potential future results, as well as to provide additional insight into the structure and characteristics of each approach. We find that, over time, certain static approaches are essentially equivalent to dynamic strategies that reduce equity exposure through time. Further, we find that most target-date fund providers appear to target a dynamic 120 - age equity allocation. We suggest that financial planners consider a 100 percent equity allocation for their clients until approximately 10 years prior to a client\u27s retirement, at which point a more conservative allocation should be employed. Although the average outcome for this approach is technically better there is still significant risk associated with this strategy. Consider the outcome should the year prior to reallocation be like 2008, or the inherent difficulties of a large shift from 100 percent equity to 45 percent equity because of tax or other issues. A more moderate reallocation over a few years may be reasonable. This flexibility suggests that financial planners can play a valuable role by helping investors determine the optimal reallocation time and process, in addition to encouraging a larger equity exposure early on to capture the benefits thereof