Portfolio Assessment in Liberal Arts Mathematics

This paper describes my efforts to incorporate problem-solving portfolios into my liberal arts mathematics course. I begin with a description of the components of the portfolios and the factors I consider in evaluating them. I then address some of the more significant obstacles I have encountered as well as what I consider to be among the major benefits. A selection from one student’s portfolio is appended

Optimised access to user analysis data using the gLite DPM

The ScotGrid distributed Tier-2 now provides more that 4MSI2K and 500TB for LHC computing, which is spread across three sites at Durham, Edinburgh and Glasgow. Tier-2 sites have a dual role to play in the computing models of the LHC VOs. Firstly, their CPU resources are used for the generation of Monte Carlo event data. Secondly, the end user analysis data is distributed across the grid to the site's storage system and held on disk ready for processing by physicists' analysis jobs. In this paper we show how we have designed the ScotGrid storage and data management resources in order to optimise access by physicists to LHC data. Within ScotGrid, all sites use the gLite DPM storage manager middleware. Using the EGEE grid to submit real ATLAS analysis code to process VO data stored on the ScotGrid sites, we present an analysis of the performance of the architecture at one site, and procedures that may be undertaken to improve such. The results will be presented from the point of view of the end user (in terms of number of events processed/second) and from the point of view of the site, which wishes to minimise load and the impact that analysis activity has on other users of the system

Commodity study: Wool production by small-scale farmers

Small-scale wool production, especially in former bantustan areas, has the potential for significant expansion and ongoing and successful farmer support should be expanded. The small proportion of sheep and wool farmers in bantustan areas who are prepared to relocate to private land, preferably in nearby districts with similar physical and climatic characteristics, should be one priority for support through land redistribution programmes. The success or failure of expanded production and class mobility should be measured over the medium to long term, including over multiple generations and may depend on ongoing and effective support programmes. New employment opportunities are likely to be modest, especially as there is very limited processing of wool before export. Farming for wool is extensive farming, optimally with low turnover but decent margins, compared to dairy farming which may also be extensive but is high in turnover with low margins. Net farm profit is a useful indicator of success or failure, rather than turnover. It may also be useful in defining emergent farmers. Net farm profit may be very different from household income as a measure of wealth/poverty and inequality. This is especially so in trust land areas where livestock and livestock products may constitute a small component of household income or a component used as savings or reserve capital for annual expenses, family events and emergencies

The Periodic Spectroscopic Variability of FU Orionis

FU Orionis systems are young stars undergoing outbursts of disc accretion and where the optical spectrum contains lines associated with both the disc photosphere and a wind component. Previous observations of the prototype FU Orionis have suggested that the wind lines and the photospheric lines are modulated with periods of 14.54 and 3.54 days respectively (Herbig et al. 2003). We have re-observed the system at higher spectral resolution, by monitoring variations of optical line profiles over 21 nights in 2007 and have found periods of 13.48 and 3.6 days in the wind and disc components consistent with the above: this implies variability mechanisms that are stable over at least a decade. In addition we have found: i) that the variations in the photospheric absorption lines are confined to the blue wing of the line (around -9km/s): we tentatively ascribe this to an orbiting hotspot in the disc which is obscured by a disc warp during its receding phase. ii) The wind period is manifested not only in blue-shifted Halpha absorption, but also in red-shifted emission of Halpha and Hbeta, as well as in blue-shifted absorption of Na I D, Li I and Fe II. iii) We find that the periodic modulation of blue-shifted Halpha absorption at around -100km/s, is phase lagged with respect to variations in the other lines by ~1.8days. This is consistent with a picture in which variations at the wind base first affect chromospheric emission and then low velocity blue-shifted absorption, followed - after a lag equal to the propagation time of disturbances across the wind's acceleration region - by a response in high velocity blue-shifted absorption. Such arguments constrain the size of the acceleration region to ~10^12cm. We discuss possible mechanisms for periodic variations within the innermost 0.1AU of the disc, including the possibility that these variations indicate the presence of an embedded hot Jupiter.Comment: 20 pages, 23 figures. Accepted for publication in MNRAS. See http://www.ast.cam.ac.uk/~slp65/FUOripaperHRes.pdf for a pdf version of the paper with high-resolution images; footnote added to the titl

Crew Exploration Vehicle Ascent Abort Overview

One of the primary design drivers for NASA's Crew Exploration Vehicle (CEV) is to ensure crew safety. Aborts during the critical ascent flight phase require the design and operation of CEV systems to escape from the Crew Launch Vehicle and return the crew safely to the Earth. To accomplish this requirement of continuous abort coverage, CEV ascent abort modes are being designed and analyzed to accommodate the velocity, altitude, atmospheric, and vehicle configuration changes that occur during ascent. The analysis involves an evaluation of the feasibility and survivability of each abort mode and an assessment of the abort mode coverage. These studies and design trades are being conducted so that more informed decisions can be made regarding the vehicle abort requirements, design, and operation. This paper presents an overview of the CEV, driving requirements for abort scenarios, and an overview of current ascent abort modes. Example analysis results are then discussed. Finally, future areas for abort analysis are addressed

The Stellar Population of h and chi Persei: Cluster Properties, Membership, and the Intrinsic Colors and Temperatures of Stars

(Abridged) From photometric observations of $\sim$ 47,000 stars and spectroscopy of $\sim$ 11,000 stars, we describe the first extensive study of the stellar population of the famous Double Cluster, h and $\chi$ Persei, down to subsolar masses. Both clusters have E(B-V) $\sim$ 0.52--0.55 and dM = 11.8--11.85; the halo population, while more poorly constrained, likely has identical properties. As determined from the main sequence turnoff, the luminosity of M supergiants, and pre-main sequence isochrones, ages for h Persei, $\chi$ Persei and the halo population all converge on $\approx$ 14 Myr. From these data, we establish the first spectroscopic and photometric membership lists of cluster stars down to early/mid M dwarfs. At minimum, there are $\sim$ 5,000 members within 10' of the cluster centers, while the entire h and $\chi$ Persei region has at least $\sim$ 13,000 and as many as 20,000 members. The Double Cluster contains $\approx$ 8,400 M$_{\odot}$ of stars within 10' of the cluster centers. We estimate a total mass of at least 20,000 M$_{\odot}$. We conclude our study by outlining outstanding questions regarding the properties of h and $\chi$ Persei. From comparing recent work, we compile a list of intrinsic colors and derive a new effective temperature scale for O--M dwarfs, giants, and supergiants.Comment: 88 pages, many figures, Accepted for publication in The Astrophysical Journal Supplements. Contact lead author for version with high-resolution figure

Establishing Applicability of SSDs to LHC Tier-2 Hardware Configuration

Solid State Disk technologies are increasingly replacing high-speed hard disks as the storage technology in high-random-I/O environments. There are several potentially I/O bound services within the typical LHC Tier-2 - in the back-end, with the trend towards many-core architectures continuing, worker nodes running many single-threaded jobs and storage nodes delivering many simultaneous files can both exhibit I/O limited efficiency. We estimate the effectiveness of affordable SSDs in the context of worker nodes, on a large Tier-2 production setup using both low level tools and real LHC I/O intensive data analysis jobs comparing and contrasting with high performance spinning disk based solutions. We consider the applicability of each solution in the context of its price/performance metrics, with an eye on the pragmatic issues facing Tier-2 provision and upgradesComment: 6 pages, 1 figure, 4 tables. Conference proceedings for CHEP201

Diurnal and stress-induced intra-hippocampal corticosterone rise attenuated in 11β-HSD1-deficient mice:a microdialysis study in young and aged mice

11β‐Hydroxysteroid dehydrogenase type 1 (11β‐HSD1) locally regenerates active glucocorticoids from their inert forms thereby amplifying intracellular levels within target tissues including the brain. We previously showed greater increases in intra‐hippocampal corticosterone (CORT) levels upon Y‐maze testing in aged wild‐type than in 11β‐HSD1(−/−) mice coinciding with impaired and intact spatial memory, respectively. Here we examined whether ageing influences 11β‐HSD1 regulation of CORT in the dorsal hippocampus under basal conditions during the diurnal cycle and following stress. Intra‐hippocampal CORT levels measured by in vivo microdialysis in freely behaving wild‐type mice displayed a diurnal variation with peak levels in the evening that were significantly elevated with ageing. In contrast, the diurnal rise in intra‐hippocampal CORT levels was greatly diminished in 11β‐HSD1(−/−) mice and there was no rise with ageing; basal intra‐hippocampal CORT levels were similar to wild‐type controls. Furthermore, a short (3 min) swim stress induced a longer lasting increase in intra‐hippocampal CORT levels in wild‐type mice than in 11β‐HSD1(−/−) mice despite no genotypic differences in elevation of plasma CORT. These data indicate that 11β‐HSD1 activity contributes substantially to diurnal and stress‐induced increases in hippocampal CORT levels. This contribution is even greater with ageing. Thus, 11β‐HSD1 inhibition may be an attractive target for treating cognitive impairments associated with stress or ageing

ScotGrid: Providing an Effective Distributed Tier-2 in the LHC Era

ScotGrid is a distributed Tier-2 centre in the UK with sites in Durham, Edinburgh and Glasgow. ScotGrid has undergone a huge expansion in hardware in anticipation of the LHC and now provides more than 4MSI2K and 500TB to the LHC VOs. Scaling up to this level of provision has brought many challenges to the Tier-2 and we show in this paper how we have adopted new methods of organising the centres, from fabric management and monitoring to remote management of sites to management and operational procedures, to meet these challenges. We describe how we have coped with different operational models at the sites, where Glagsow and Durham sites are managed "in house" but resources at Edinburgh are managed as a central university resource. This required the adoption of a different fabric management model at Edinburgh and a special engagement with the cluster managers. Challenges arose from the different job models of local and grid submission that required special attention to resolve. We show how ScotGrid has successfully provided an infrastructure for ATLAS and LHCb Monte Carlo production. Special attention has been paid to ensuring that user analysis functions efficiently, which has required optimisation of local storage and networking to cope with the demands of user analysis. Finally, although these Tier-2 resources are pledged to the whole VO, we have established close links with our local physics user communities as being the best way to ensure that the Tier-2 functions effectively as a part of the LHC grid computing framework..Comment: Preprint for 17th International Conference on Computing in High Energy and Nuclear Physics, 7 pages, 1 figur

Sheep Updates 2006 - part 3

This session covers six papers from different authors: GRAZING 1. Making better use of clover, Karen Venning and Andrew Thompson, Department of Primary Industries, Victoria 2. Grazing systems demonstration to optimise pasture utilisation and stocking rate, Mike Hyder, Sue-Ellen Shaw, Kelly Hill and Ron McTaggart, Department of Agriculture and Food Western Australia. 3. Know your audience to increase their rate of practice change - Lifetime Wool as an example, Gus Rose, Department of Agriculture and Food Western Australia, Carolyn Kabore, Kazresearch REPRODUCTION 4. Lifetime Wool - Ewe Management Guidlines, Mandy Curnow, Department of Agriculture and Food Western Australia 5. Achieving the best reproductive performance from your hoggets, Kenyon PR, Morris ST, West DM, Perkins NR, Pinchbeck GL., Institute of Veterinary, Animal and Biomedical Sciences, Massey University, New Zealand. 6. Lifetime Wool: Twin futures, Dr Ralph Behrendt, Department of Primary Industries, Victori