Developing an Ontario Maple Syrup Sector Profile: A Value Chain Analysis (Executive Summary)

Through a sectorial profile, this study identifies the maple syrup value chain’s key players, processes, activities and inter-intra industry relationships (social capital) providing baseline data on the current status of the industry and an overall picture of the maple syrup value chain for members and new entrants. The study found that a) technological advancements over the years have lead to great efficiencies and eased the labour requirement; b) that strong social connections have great impact on marketing and retail of syrup; c) that innovation is found not only through research and development sectors of large companies but also from a bottom-up approach; d) Producers have aided with innovations with development of technology and processes

Maple Syrup Value Systems and Value Chains - Considering Aboriginal and Non-Aboriginal Perspectives

Harvested from both intensive sugar maple stands and diverse mixed forest ecosystems across Ontario, maple syrup is an important rural and Aboriginal non-timber forest product that contributes to social, economic and environmental sustainability. This paper presents our ongoing work to map Ontario’s maple syrup value system from two different perspectives, Aboriginal and non-Aboriginal. In the economic sense, analyses of value systems are useful for members to identify the opportunities and challenges they are facing to advance industry growth and innovation. In the social and environmental sense, these analyses provide a window into how different worldviews and belief systems can lead to more effective and sustainable maple production. A value system is the inter-connected network of firms and activities that comprise an industry from the supplier to the consumer that is focused on quality and efficiency rather than costs. In this project, we pushed the boundaries of the traditional business approach, to incorporate sustainable development thinking and re-imagine the mapping according to Aboriginal ways of knowing. We undertook thirty four interviews representing Aboriginal and rural industry members and other key informants. We compare and contrast the rural and Aboriginal models of the value systems and conclude by providing insights useful for community forestry operations

Sub-2 cm/s passivation of silicon surfaces by aprotic solutions

Minimizing recombination at semiconductor surfaces is required for the accurate determination of the bulk carrier lifetime. Proton donors, such as hydrofluoric acid and superacids, are well known to provide highly effective short-term surface passivation. We demonstrate here that aprotic solutions based on bis(trifluoromethanesulfonyl)methane (TFSM) in hexane or pentane can also result in excellent passivation of (100)-orientation silicon surfaces. We show that the optimized TFSM-pentane passivation scheme can measure effective lifetimes up to 20 ms, with a surface recombination velocity of 1.7 cm s1 at an excess carrier density of 1015 cm3 . Fitting injection-dependent lifetime curves requires chemical passivation and field effect passivation from a negatively charged layer with a charge density of 1010–1011 q cm2 . The slightly higher recombination velocity of 2.3 cm s1 measured with TFSM-hexane can be explained by a lower charge density in the passivating layer, suggesting that the steric hindrance associated with the solvent size could play a role in the passivation mechanism. Finally, phosphorus nuclear magnetic resonance experiments confirm that TFSM-based solutions have Lewis acidity without being superacids, which opens up opportunities for them to be used in materials systems sensitive to superacidic environments

Low-temperature saw damage gettering to improve minority carrier lifetime in multicrystalline silicon

The minority carrier lifetime in multicrystalline silicon − a material used in the majority of today's manufactured solar cells − is limited by defects within the material, including metallic impurities which are relatively mobile at low temperatures (≤700 °C). Addition of an optimised thermal process which can facilitate impurity diffusion to the saw damage at the wafer surfaces can result in permanent removal of the impurities when the saw damage is etched away. We demonstrate that this saw damage gettering is effective at 500 to 700 °C and, when combined with subsequent low-temperature processing, lifetimes are improved by a factor of more than four relative to the as-grown state. The simple method has the potential to be a low thermal budget process for the improvement of low-lifetime “red zone” wafers

Body size and symbiotic status influence gonad development in \u3cem\u3eAiptasia pallida\u3c/em\u3e anemones

Pale anemones (Aiptasia pallida) coexist with dinoflagellates (primarily Symbiodinium minutum) in a mutualistic relationship. The purpose of this study was to investigate the role of these symbionts in gonad development of anemone hosts. Symbiotic and aposymbiotic anemones were subjected to light cycles that induced gametogenesis. These anemones were then sampled weekly for nine weeks, and gonad development was analyzed histologically. Anemone size was measured as mean body column diameter, and oocytes or sperm follicles were counted for each anemone. Generalized linear models were used to evaluate the influence of body size and symbiotic status on whether gonads were present and on the number of oocytes or sperm follicles produced. Body size predicted whether gonads were present, with larger anemones being more likely than smaller anemones to develop gonads. Both body size and symbiotic status predicted gonad size, such that larger and symbiotic anemones produced more oocytes and sperm follicles than smaller and aposymbiotic anemones. Overall, only 22 % of aposymbiotic females produced oocytes, whereas 63 % of symbiotic females produced oocytes. Similarly, 6 % of aposymbiotic males produced sperm follicles, whereas 60 % of symbiotic males produced sperm follicles. Thus, while gonads were present in 62 % of symbiotic anemones, they were present in only 11 % of aposymbiotic anemones. These results indicate that dinoflagellate symbionts influence gonad development and thus sexual maturation in both female and male Aiptasia pallida anemones. This finding substantiates and expands our current understanding of the importance of symbionts in the development and physiology of cnidarian hosts

Exploring protein backbone designability: the computational redesign and de novo design of helix bundle proteins

Protein design rigorously tests our mastery of protein folding, stability and function. Protein design can be separated into redesign and de novo design by the issue of designability, which states that not all protein backbones will lead to viable sequences. The goal of redesign is to find favorable sequences for proteins with known structures, using their experimental coordinates as design models. De novo design requires design model coordinates to be created from scratch and then finds favorable sequences. Nature provides designable backbones in the case of fixed backbone redesign. In flexible redesign and de novo design, however, we have no guarantee of designability. This work develops computational methods for flexible redesign and de novo design of diverse protein folds, probing questions of designability. We successfully used flexible redesign on several helix-bundle proteins and solved X-ray and NMR structures for one redesigned protein. The design model and the experimental structures are highly similar, less than 1.0 angstrom backbone rsmd. Our success in de novo design has been modest. We have not succeeded in the de novo design of an all beta-fold and continue to pursue this challenge. We have succeeded in the de novo design of a four helix-bundle protein. Preliminary NMR data suggests our design model and the experimental structure are the same fold and are similar at a global level with a backbone rmsd of less than or equal to 3 angstroms

Iodine-ethanol surface passivation for measurement of millisecond carrier lifetimes in silicon wafers with different crystallographic orientations

To improve silicon device fabrication processes it is necessary to monitor bulk minority carrier lifetimes accurately, and this requires surface recombination to be well controlled and, ideally, minimized. Good surface passivation can result from thermal oxidation or by deposition of dielectrics (e.g. Al2O3, SiNx, amorphous Si), but these forms of passivation can modify the lifetime of the material under investigation. Various schemes can passivate surfaces on a temporary basis without modifying the bulk, and, in this paper, the virtues of the iodine‐ethanol temporary surface passivation scheme are explored. A procedure for preparing the wafer surfaces prior to passivation is developed. For the optimised pre‐treatment, a series of experiments on 3–5 Ωcm float‐zone wafers cut from the same ingot with different thicknesses is conducted. This enables the material's bulk lifetime to be measured at 1015 cm−3 injection as ≈46 ms, with the surface recombination velocity being 6.5 ± 0.3 cm s−1. Iodine‐ethanol passivation is then compared to a recently developed superacid‐derived temporary passivation scheme. Although the latter is superior on (100)‐orientation substrates, iodine‐ethanol performs much better on (111)‐orientation substrates, making it a better choice for (111)‐orientation wafers, such as those used for power devices

The College News, 1936-04-08, Vol. 22, No. 19

Bryn Mawr College student newspaper. Merged with The Haverford News in 1968 to form the Bi-college News (with various titles from 1968 on). Published weekly (except holidays) during the academic year

Leaf Herbivory Induces Resistance Against Florivores In \u3ci\u3eRaphanus sativus\u3c/i\u3e

Florivory can have significant negative effects on plant fitness, driving selection for resistance traits in flowers. In particular, herbivory to leaves may induce resistance in flowers because herbivores on leaves often become florivores on flowers as plant ontogeny proceeds. The literature on inducible resistance in floral tissues is limited, so we used a series of experiments to determine whether prior leaf damage by Spodoptera exigua (Hübner) caterpillars affected florivore preference and performance on wild radish (Raphanus sativus L.). We found that Spodoptera exigua larvae preferred petals from control plants versus petals from plants exposed to prior leaf damage, and that larvae gained more mass on petals from control plants, although this depended on the presence of anthocyanins in the petals. Our results suggest that leaf damage can induce changes in petals that reduce Spodoptera exigua larval fitness