The portormin (dunbeath) runestone

A stone with a short runic inscription was discovered on the beach at Portormin Harbour in Dunbeath, Caithness, in 1996. The find attracted some press attention at the time, but has been largely ignored by the runological com­mu­nity amid doubts over its authenticity. There has, however, been no detailed dis­cussion of the stone in a public arena. A description of the inscription is followed by discussion of several interpretations. There are good reasons for suspecting that the carvings are of modern origin, but the matter cannot be settled with certainty; the case invites comparison with the controversies sur­rounding runic inscriptions in North America

Learning and understanding in abstract algebra

Students\u27 learning and understanding in an undergraduate abstract algebra class were described using Tall and Vinner\u27s notion of a concept image, which is the entire cognitive structure associated with a concept, including examples, nonexamples, definitions, representations, and results. Prominent features and components of students\u27 concept images were identified for concepts of elementary group theory, including group, subgroup, isomorphism, coset, and quotient group. Analysis of interviews and written work from five students provided insight into their concept images, revealing ways they understood the concepts. Because many issues were related to students\u27 uses of language and notation, the analysis was essentially semiotic, using the linguistic, notational, and representational distinctions that the students made to infer their conceptual understandings and the distinctions they were and were not making among concepts. Attempting to explain and synthesize the results of the analysis became a process of theory generation, from which two themes emerged: making distinctions and managing abstraction. The students often made nonstandard linguistic and notational distinctions. For example, some students used the term coset to describe not only individual cosets but also the set of all cosets. This kind of understanding was characterized as being immersed in the process of generating all of the cosets of a subgroup, a characterization that described and explained several instances of the phenomenon of failing to distinguish between a set and its elements. The students managed their relationships with abstract ideas through metaphor, process and object conceptions, and proficiency with concepts, examples, and representations. For example, some students understood a particular group by relying upon its operation table, which they sometimes took to be the group itself rather than a representation. The operation table supported an object conception even when a student had a fragile understanding of the processes used in forming the group. Making distinctions and managing abstraction are elaborated as fundamental characteristics of mathematical activity. Mathematics thereby becomes a dialectic between precision and abstraction, between logic and intuition, which has important implications for teaching, teacher education, and research

Climate coupling between temperature, humidity, precipitation, and cloud cover over the Canadian prairies

This analysis uses over 50 years of hourly observations of temperature, relative humidity, and opaque cloud cover and daily precipitation from 11 climate stations across the Canadian Prairies to analyze the monthly, seasonal, and long-term climate coupling in the warm season. On climate time scales, temperature depends on cloud forcing, while relative humidity depends on precipitation. The monthly climate depends on both opaque cloud cover for the current month and precipitation for both the present and past 2 months in summer. Multiple linear regression shows that anomalies of opaque cloud and precipitation explain 60–80% of the variance in the diurnal temperature range, afternoon relative humidity, and lifting condensation level on monthly time scales. We analyze the internal coupling of diurnal climate observables as a further guide to evaluating models. We couple the statistics to simplified energy and water budgets for the Prairies in the growing season. The opaque cloud observations have been calibrated against the incoming shortwave and longwave fluxes. We estimate that the drydown of total water storage on the landscape damps 56% of precipitation anomalies for the growing season on large spatial scales, although this drydown increases evapotranspiration. This couples the climatological surface fluxes to four key observables: cloud forcing, precipitation, temperature, and humidity. We estimate a climatological evaporative fraction of 0.61 for the Prairies. The observational relationships of the coupled Prairie climate system across time scale will be useful for evaluating these coupled processes in models for weather and seasonal forecasting and climate simulation

Vocalism in the Continental runic inscriptions

The goal of this thesis is the phonological analysis of a corpus of runic inscriptions in order to reconstruct the vocalic system(s) of the West Germanic dialects spoken in the Continental interior between the 5th-7th centuries A.D. The thesis presents a brief outline of the late Proto-Germanic vocalic system and of the principal sound changes involved in the development of the later dialects of the region (Old High German and Old Saxon). The main part of the thesis surveys the data retrievable from the runic inscriptions in an attempt to determine to what extent (if any) these sound changes are in evidence. In many respects, the data are consistent with the anticipated developments attested in OHG and OS; but for some of the sound changes – particularly those affecting the diphthongs – the existing models do not satisfactorily account for the data. There is also some evidence for processes not normally identified in accounts of the phonological background of the later dialects. The project endeavours to be rigorously empirical in approach; to avoid making unnecessary assumptions and prejudgements about the nature and content of the runic texts; and to resist the rejection of an interpretation unless it can be shown to be implausible. From this standpoint, we are confronted with the limited power of any conclusions based on such a small dataset, and with the more general problem of the imperfect correlation between written and spoken forms. If the makers of runic inscriptions cannot be relied on for phonological accuracy or orthographic consistency, to what extent is it possible to make inferences about spoken language from the texts which they created

A model of evaluative opinion to encourage greater transparency and justification of interpretation in post-mortem forensic toxicology

Over the past decades, the calls to improve the robustness of interpretation in forensic science have increased in magnitude. Forensic toxicology has seen limited progress in this regard. In this work, we propose a transparent interpretive pathway for use in postmortem forensic toxicology cases. This process allows the selection of the interpretive methodology based on the amount of previous information that is available for the drug(s) in question. One approach is an assessment of various pharmacological and circumstantial considerations resulting in a toxicological significance score (TSS), which is particularly useful in situations where limited information about a drug is available. When there is a robust amount of case data available, then a probabilistic approach, through the evaluation of likelihood ratios by the forensic toxicologist and of prior probabilities by the fact finder, is utilized. This methodology provides a transparent means of making an interpretive decision on the role of a drug in the cause of death. This will allow the field of forensic toxicology to take a step forward in using best practice in evaluative reporting, a tool already used by many other forensic science disciplines.</p

Precipitation Sensitivity to Surface Heat Fluxes over North America in Reanalysis and Model Data

A new methodology for assessing the impact of surface heat fluxes on precipitation is applied to data from the North American Regional Reanalysis (NARR) and to output from the Geophysical Fluid Dynamics Laboratory’s Atmospheric Model 2.1 (AM2.1). The method assesses the sensitivity of afternoon convective rainfall frequency and intensity to the late-morning partitioning of latent and sensible heating, quantified in terms of evaporative fraction (EF). Over North America, both NARR and AM2.1 indicate sensitivity of convective rainfall triggering to EF but no appreciable influence of EF on convective rainfall amounts. Functional relationships between the triggering feedback strength (TFS) metric and mean EF demonstrate the occurrence of stronger coupling for mean EF in the range of 0.6 to 0.8. To leading order, AM2.1 exhibits spatial distributions and seasonality of the EF impact on triggering resembling those seen in NARR: rainfall probability increases with higher EF over the eastern United States and Mexico and peaks in Northern Hemisphere summer. Over those regions, the impact of EF variability on afternoon rainfall triggering in summer can explain up to 50% of seasonal rainfall variability. However, the AM2.1 metrics also exhibit some features not present in NARR, for example, strong coupling extending northwestward from the central Great Plains into Canada. Sources of disagreement may include model hydroclimatic biases that affect the mean patterns and variability of surface flux partitioning, with EF variability typically much lower in NARR. Finally, the authors also discuss the consistency of their results with other assessments of land–precipitation coupling obtained from different methodologies

Scaling in Surface Hydrology: Progress and Challenges

This paper presents a review of the challenges in spatial and temporal scales in surface hydrology. Fundamental issues and gaps in our understanding of hydrologic scaling are highlighted and shown to limit predictive skill, with heterogeneities, nonlinearities, and non-local transport processes among the most significant difficulties faced in scaling. The discrepancy between the physical process scale and the measurement scale has played a major role in restricting the development of theories, for example, relating observational scales to scales of climate and weather models. Progress in our knowledge of scaling in hydrology requires systematic determination of critical scales and scale invariance of physical processes. In addition, viewing the surface hydrologic system as composed of interacting dynamical subsystems should facilitate the definition of scales observed in nature. Such an approach would inform the development of careful, resolution-dependent, physical law formulation based on mathematical techniques and physical laws

Runes and commemoration in Anglo-Saxon England

Runic inscriptions are of interest not only as evidence of language and literacy in early medieval England, but also of the cultural functions of the objects on which they appear. In this paper, we present three case studies to examine the ways in which runic writing was used to commemorate the dead in Anglo-Saxon England: a cremation urn from Loveden Hill, Lincolnshire; the wooden coffin of Saint Cuthbert; and a carved memorial stone from Great Urswick, Cumbria. Our study highlights the diversity of rune-inscribed objects in their material and function, from containers for human remains to monuments on public display. In each case we discuss the linguistic problems of the text and the relationship of the inscription to the object and its find context, before turning to a broader examination of the role of inscribed objects in the act of commemoration and the question of the choice of runic over the Roman script

Atmospheric controls on soil moisture-boundary layer interactions

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (leaves 163-168).This thesis addresses the question of how the early morning atmospheric thermodynamic structure affects the interaction between the soil moisture state and the growth and development of the boundary layer (BL), leading to the triggering of convection. It is concluded that in mid-latitudes, for matters of convective triggering and response to land surface conditions, the critical portion of the atmospher~approximately1 to 3 km above the ground surface is independent of geographic location and local synoptic setting. As long as the low levels of the troposphere are relatively humid but not extremely close to saturation, a negative feedback between soil moisture and rainfall is likely when the early morning temperature lapse rate in this region is dry adiabatic; a positive feedback is likely when it is moist adiabatic; and when there is a temperature inversion in this region, deep convection cannot occur, independent of the soil moisture. Additionally, when the low levels of the troposphere are extremely dry or very close to saturation, the occurrence of convection is determined solely by the atmospheric conditions. Essential characteristics of the temperature structure of the early-morning atmosphere are captured by a new thermodynamic measure, the Convective Triggering Potential (CTP), developed to distinguish between soundings favoring rainfall over dry soils from those favoring rainfall over wet soils. Many measures of atmospheric humidity are effective at separating atmospherically-controlled cases from cases where the land surface conditions can influence the likelihood for convection, but Hi low, a variation of a humidity index, proved most effective. A one-dimensional model of the planetary boundary layer (BL) and surface energy budget has been modified to allow the growing BL to entrain air from an observed atmospheric sounding. The model is used to analyze the impact of soil saturation on BL development and the triggering of convection in different atmospheric settings. Results from this 1D model and from the three-dimensional Fifth-Generation Penn State/NCAR Mesoscale Model (MM5) show a small but significant positive soil moisture-rainfall feedback in Illinois. This is consistent with an analysis of the distribution of early morning sounding values of CTP and Hi low from Illinois, though wind effects important in the MM5 simulations are not captured by the CTP-HIhow framework. From the MM5 simulations, it is concluded that the land surface condition can impact the potential for convection only when the atmosphere is not already predisposed to convect or not to convect. This atmospheric predisposition can be determined by analyzing the CTP, the Hi low, and the vertical profile of the winds. Analyses of Hi low scatter plots from radiosonde stations across the contiguous 48 United States reveal that positive feedbacks are likely in much of the eastern half of the country. The only area showing a potential negative feedback is in the Dryline and Monsoon Region of the arid southwest. Land surface conditions are unlikely to impact convective triggering in the rest of the western half of the country. Use of the lD BL model at four additional stations confirms that HilowTP-Hi low framework used in this nationwide analysis is valid for regions far removed from Illinois, where it was originally developed.by Kirsten Lynn Findell.Ph.D