A ’Millipede’ scanner model - Energy consumption and performance

This short report (1) describes an energy model for the seek and read/write operations in a mass-balanced Y-scanner for parallel-probe storage by IBM [1] and (2) updates the settings of the MEMS model in DiskSim with recent published figures from this XY-scanner. To speedup system simulations, a straight forward second-order model is used without control loop. Read/write operation is modeled by quasi-static calculations. To approximate seek behavior, ’bang-bang’ control is assumed; the result is close to the actual behavior with control loop [2]. Unfortunately, no energy measurements were available to validate the model. Using the proposed energy model, we are able to study the energy consumption of a MEMS-based storage device for different application areas and file systems

Energy-Efficient Streaming Using Non-volatile Memory

The disk and the DRAM in a typical mobile system consume a significant fraction (up to 30%) of the total system energy. To save on storage energy, the DRAM should be small and the disk should be spun down for long periods of time. We show that this can be achieved for predominantly streaming workloads by connecting the disk to the DRAM via a large non-volatile memory (NVM). We refer to this as the NVM-based architecture (NVMBA); the conventional architecture with only a DRAM and a disk is referred to as DRAMBA. The NVM in the NVMBA acts as a traffic reshaper from the disk to the DRAM. The total system costs are balanced, since the cost increase due to adding the NVM is compensated by the decrease in DRAM cost. We analyze the energy saving of NVMBA, with NAND flash memory serving as NVM, relative to DRAMBA with respect to (1) the streaming demand, (2) the disk form factor, (3) the best-effort provision, and (4) the stream location on the disk. We present a worst-case analysis of the reliability of the disk drive and the flash memory, and show that a small flash capacity is sufficient to operate the system over a year at negligible cost. Disk lifetime is superior to flash, so that is of no concern

Doctors who pilot the GMC's Tests of Competence: who volunteers and why?

Background: Doctors who are investigated by the General Medical Council (GMC) for performance concerns may be required to take a Test of Competence (ToC). The tests are piloted on volunteer doctors before they are used in Fitness to Practise (FtP) investigations. Objectives: To find out who volunteers to take a pilot ToC and why. Methods: This was a retrospective cohort study. Between February 2011 and October 2012 we asked doctors who volunteered for a test to complete a questionnaire about their reasons for volunteering and recruitment. We analysed the data using descriptive statistics and Pearson’s chi-square test. Results: 301 doctors completed the questionnaire. Doctors who took a ToC voluntarily were mostly women, of white ethnicity, of junior grades, working in general practice and who held a Primary Medical Qualification from the UK. This was a different population to doctors under investigation and all registered doctors in the UK. Most volunteers heard about the GMC’s pilot events through email from a colleague and used the experience to gain exam practice for forthcoming postgraduate exams. Conclusions: The reference group of volunteers are not representative of doctors under FtP investigation. Our findings will be used to inform future recruitment strategies with the aim to encourage better matching of groups who voluntarily pilot a ToC with those under FtP investigation

How migrating 0.0001% of address space saves 12% of energy in hybrid storage

We present a simple, operating-\ud system independent method to reduce the num-\ud ber of seek operations and consequently reduce\ud the energy consumption of a hybrid storage\ud device consisting of a hard disk and a flash\ud memory. Trace-driven simulations show that\ud migrating a tiny amount of the address space\ud (0.0001%) from disk to flash already results\ud in a significant storage energy reduction (12%)\ud at virtually no extra cost. We show that the\ud amount of energy saving depends on which part\ud of the address space is migrated, and we present\ud two indicators for this, namely sequentiality and\ud request frequency. Our simulations show that\ud both are suitable as criterion for energy-saving\ud file placement methods in hybrid storage. We\ud address potential wear problems in the flash\ud subsystem by presenting a simple way to pro-\ud long its expected lifetime.\u

How well do doctors think they perform on the General Medical Council's Tests of Competence pilot examinations? A cross-sectional study.

To investigate how accurately doctors estimated their performance on the General Medical Council's Tests of Competence pilot examinations

The effectiveness of BBC Bitesize for learning science by KS3 learners in the UK

There are a number of studies arguing for and against the use of Online learning resources for learning facilitation. Some studies attribute the rise of learners’ achievement to the use of technology; others believe that technology has changed the learners’ attitudes towards learning. Scholars have used learners’ attitudes and achievement as indicators of the success or the failure of technology. The majority of extant related research is carried out at University, College and further education levels but limited studies have examined KS3 learners in the UK. In particular, there are not a lot of studies that focus on measuring the learning effectiveness through KS3 learners’ attitude and achievement at the same time. The present study uses both attitudes and achievement and the link between them as a predictor of the BBC Bitesize online learning resource effectiveness. This case study aims to examine the use of BBC Bitesize and identify its effectiveness for learning Science in Year 9 in two Schools in Manchester, UK. Subsequently, the present study investigates these 3 themes:a.The effect of Computers & BBC Bitesize on KS3 learners’ attitudes.b.The impact of Computers & BBC Bitesize on KS3 learners’ achievement and learning effectiveness.c.The correlation between the learners’ attitudes towards BBC Bitesize and their achievement.This study is a mixed methods study that combines both quantitative and qualitative data. The quantitative research method is reflected through the use of 121 attitudinal questionnaires. The qualitative research method in this study is represented by 11 semi-structured interviews The study traces the learners’ achievement by using a written test after they have been given a Science course via BBC Bitesize.Attitudes have been approached in a way that defines an attitude as the combination of a number of factors: affective component, perceived-usefulness, perceived-control, behavioural component, anxiety component and self-efficacy component. These components have been the base of the study questionnaire based on Selwyn’s (1997) model.The contribution to knowledge is in the area of debate on whether Online learning can improve learner’s achievement. In particular, the current study makes the following contributions to knowledge for KS3 -related Online learning using BBC Bitesize: a.Development of a new scale for measuring learners’ attitude using socio-psychological factors and identifying that two of these – control and anxiety- are not significant; b.The attitude and achievement constructs are studied together using partial correlation analysis and Spearman correlation, and a positive link is found suggesting that positive attitude has a positive impact on achievement; c.The components of attitudes are confirmed as: affective, usefulness, behavioural and self-efficacy. This amends the original four components from Selwyn. The current study has a practical contribution in that it confirms that BBC Bitesize has positively affected the learners’ achievement and attitudes. BBC Bitesize is found to be effective for facilitating learning of Science by KS3 learners

Enantiomeric oxidation of organic sulfides by the filamentous fungi Botrytis cinerea, Eutypa lata and Trichoderma viride

The biotransformations of a series of substituted sulfides were carried out with the filamentous fungi Botrytis cinerea, Eutypa lata and Trichoderma viride. Several products underwent microbial oxidation of sulfide to sulfoxide with medium to high enantiomeric purity. With regard to sulfoxide enantioselectivity, the (R)-enantiomer was favoured in biotransformations by T. viride and E. lata while the (S)-enantiomer was favoured in those by B. cinerea. A minor amount of sulfone product was also obtained