Interpolation Problem by IBM 1620, as Told to Dave Reid

In lieu of an abstract, below is the essay\u27s first paragraph. Editor\u27s Note: The increasingly important role played by computers in our modern world has not passed by the staff of this magazine unnoticed. Indeed, we can even foresee a new use for these mechanical masterminds-the writing of poetry. To prove our point, we bring to your attention part of a simple math problem. But note the view of life it presents, especially in the last ten lines

Coarse Woody Debris Dynamics Following Biomass Harvesting: Tracking Carbon and Nitrogen Patterns During Early Stand Development in Upland Black Spruce Ecosystems

Coarse woody debris (CWD) in the boreal ecosystem has been hypothesized to play an important nutritional role following stand-replacing disturbances such as fire or harvest. Sites with shallow soil over bedrock, or those with coarse-textured soils, can be especially susceptible to overstory removal because low carbon and nutrient pools may limit stand productivity in subsequent rotations. On these site types, CWD can provide essential nutrition to the developing second growth stand, prior to internal cycling processes stabilizing at crown closure (15 years to 20 years after stand initiation) through slow and steady decomposition. The current study sites were established in 1994 and in 2008 (14 years following harvesting) and were approaching crown closure. The experimental harvest areas were designed to document carbon loss and nutrient fluxes after the application of four levels of biomass removal from mature black spruce forested stands in northwestern Ontario, Canada. Two soil types (fresh, loamy: dry, sandy), with stand replicates (blocks), were selected to test whether residual CWD represents a source or sink for nutrients, and if the decay pattern varied depending on soil type. Measurement/sampling of CWD was done immediately after the harvest treatments were applied, and again in year 4 and year 14. The biomass removal treatment with the greatest carbon loss and fastest CWD decay rate had the highest initial mass of CWD, indicating possible synergistic decay dynamics. Nitrogen concentration in the CWD continued to increase from the initial measurements to year 14 (from 900 ppm to 2400 ppm), but was largely a function of increasing carbon loss. When converted to N content in CWD (kg ha-1), however, nitrogen exhibited an initial upward trend (i.e., immobilization) through years 1to 4 (from 50 kg ha-1 up to 80 kg ha-1) and a subsequent release in years 5 to 14 (from 80 kg ha-1down to 27 kg ha-1). This trend was more apparent on the dry, sandy sites where N content peaked at almost 100 kg ha-1 at year 4, but then reduced to 26 kg ha-1 by year 14. We compared the average loss of N from CWD in years 4 to 14 (5.3 kg ha-1 yr-1) to the total soil inorganic N pool (based on a fresh K2SO4 extraction), and found that the N loss from CWD represented a substantive portion (80%) of the available N pool, particularly on the dry, sandy sites. After an initial peak in year 4, black spruce foliar N decreased significantly (p<.0001) through to year 10 but began to rebound by year 15. This increase, presumably, was in part the result of the documented release of N from CWD. These results suggest that CWD, although a small contributor to the total N pool, makes a substantial contribution to the relatively small available N pool, especially on dry, sandy soils. The trend of initial N immobilization and subsequent release shows CWD may also serve to buffer the initial leaching of nutrients from the site following harvesting and provide an available source of N to the regenerating stand prior to crown closure. Keywords: coarse woody debris, black spruce, carbon and nitrogen dynamics. Received 23 September 2010, Revised 11 December 2012, Accepted 13 December 2012

21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing

Abstract Kraak, S. B. M., Reid, D. G., Gerritsen, H. D., Kelly, C. J., Fitzpatrick, M., Codling, E. A., and Rogan, E. 2012. 21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing. – ICES Journal of Marine Science, 69: 590–601. Traditionally fisheries management has focused on biomass and mortality, expressed annually and across large management units. However, because fish abundance varies at much smaller spatio-temporal scales, fishing mortality can potentially be controlled more effectively if managed at finer scale. The ecosystem approach requires more indicators at finer scales as well. Incorporating ecosystem targets would need additional management tools with potentially conflicting results. We present a simple, integrated, management approach that provides incentives for “good behaviour”. Fishers would be given a number of fishing-impact credits, called real-time incentives (RTIs), to spend according to spatio-temporally varying tariffs per fishing day. RTI quotas and tariffs could be based on commercial stocks and ecosystem targets. Fishers could choose how to spend their RTIs, e.g. by limited fishing in high-catch or sensitive areas or by fishing longer in lower-catch or less sensitive areas. The RTI system does not prescribe and forbid, but instead allows fishers to fish wherever and whenever they want; ecosystem costs are internalized and fishers have to take them into account in their business decisions. We envisage no need for traditional landings or catch quotas for the fleets while operating under the scheme. The approach could facilitate further devolution of responsibility to industry.</jats:p

Estimating influenza incidence using search query deceptiveness and generalized ridge regression

Seasonal influenza is a sometimes surprisingly impactful disease, causing thousands of deaths per year along with much additional morbidity. Timely knowledge of the outbreak state is valuable for managing an effective response. The current state of the art is to gather this knowledge using in-person patient contact. While accurate, this is time-consuming and expensive. This has motivated inquiry into new approaches using internet activity traces, based on the theory that lay observations of health status lead to informative features in internet data. These approaches risk being deceived by activity traces having a coincidental, rather than informative, relationship to disease incidence; to our knowledge, this risk has not yet been quantitatively explored. We evaluated both simulated and real activity traces of varying deceptiveness for influenza incidence estimation using linear regression. We found that deceptiveness knowledge does reduce error in such estimates, that it may help automatically-selected features perform as well or better than features that require human curation, and that a semantic distance measure derived from the Wikipedia article category tree serves as a useful proxy for deceptiveness. This suggests that disease incidence estimation models should incorporate not only data about how internet features map to incidence but also additional data to estimate feature deceptiveness. By doing so, we may gain one more step along the path to accurate, reliable disease incidence estimation using internet data. This capability would improve public health by decreasing the cost and increasing the timeliness of such estimates.Comment: 27 pages, 8 figure

DLR Covid-19 Mobility Review: Evaluation and Review of the Phase 1 Covid-19 Mobility and Public Realm Works undertaken by Dún Laoghaire Rathdown County Council

Evaluation and Review of the Phase 1 Covid-19 Mobility and Public Realm Works undertaken by Dún Laoghaire- Rathdown County Council. Interim findings, June 2021