Loops and quasigroups: Aspects of current work and prospects for the future

summary:This paper gives a brief survey of certain recently developing aspects of the study of loops and quasigroups, focussing on some of the areas that appear to exhibit the best prospects for subsequent research and for applications both inside and outside mathematics

Clustering-Based Materialized View Selection in Data Warehouses

Materialized view selection is a non-trivial task. Hence, its complexity must be reduced. A judicious choice of views must be cost-driven and influenced by the workload experienced by the system. In this paper, we propose a framework for materialized view selection that exploits a data mining technique (clustering), in order to determine clusters of similar queries. We also propose a view merging algorithm that builds a set of candidate views, as well as a greedy process for selecting a set of views to materialize. This selection is based on cost models that evaluate the cost of accessing data using views and the cost of storing these views. To validate our strategy, we executed a workload of decision-support queries on a test data warehouse, with and without using our strategy. Our experimental results demonstrate its efficiency, even when storage space is limited

A New Look at Bandwidth Latency Tradeoffs

Concerns about propagation delay have dominated the discussion of latency, bandwidth and their effect on distributed applications. In this paper, we argue that the relevant latency measure for applications is the Application Data Unit (ADU) Latency, defined as the time between the sending of an ADU and its receipt. Since ADUs are often large, ADU latency is influenced by throughput as well as propagation delay. We investigated the effects the effects of ADU latency with an experimental study of several applications. The applications used Distributed Shared Memory as an interprocess communications mechanism, constraining the ADUs to page sized units. The applications were run on an Ethernet, an experimental ATM LAN, and using ATM on an experimental high-speed WAN. The measured results were used to normalize results gathered by inserting an experimental ATM switch output port controller in the network to create tunable delays. The results conclusively demonstrate the effect of ADU latency on distributed application response time. The experiments give a precise characterization of the effect of varying bandwidth and propagation delay on a real system, and suggest promising directions for further improving application performance in future networks

Evaluations of Neurologists by Their Patients and Residents Are Inversely Correlated

Objective and Background: We hypothesized that evaluation scores for attending neurologists by patients and residents would parallel one another. Additionally, we hypothesized that provider productivity would be also be associated with performance evaluations by patients and residents. Methods: In a university neurology department, we collected individual Clinician and Group Consumer Assessment of Healthcare Providers and Systems patient satisfaction scores and standardized resident evaluation scores (n = 22 faculty members). We performed bivariate analysis of doctor–patient satisfaction versus resident evaluation scores. Results: Attending neurologists with higher patient satisfaction received lower resident evaluation scores (P \u3c .05). There seem to be disproportionate neurologists with low evaluations not meeting clinical productivity targets. Conclusion: Finding a significant inverse correlation was surprising. Perhaps what is valued by patients in their physician is not what residents value in teachers. That deserves further study. Maybe attending physicians who spend their energy on the patient experience do not have sufficient time to devote to teaching and vice versa. That neurologists with low evaluation scores appear more likely to not meet productivity targets supports this idea

Road to Ruin: Targeting Proteins for Degradation in the Endoplasmic Reticulum

Some nascent proteins that fold within the endoplasmic reticulum (ER) never reach their native state. Misfolded proteins are removed from the folding machinery, dislocated from the ER into the cytosol, and degraded in a series of pathways collectively referred to as ER-associated degradation (ERAD). Distinct ERAD pathways centered on different E3 ubiquitin ligases survey the range of potential substrates. We now know many of the components of the ERAD machinery and pathways used to detect substrates and target them for degradation. Much less is known about the features used to identify terminally misfolded conformations and the broader role of these pathways in regulating protein half-lives.National Institutes of Health (U.S.

Reliability assessment and criticality analysis for Wave Energy Converters

This paper applies existing reliability methods, namely Reliability Block diagrams, to a notional wave energy converter configuration. It shows possible source of information and difficulties associated with an omnipresent lack of failure rate data.The reliability of wave energy converters (WECs) is a key issue that has to be addressed in order to make them a viable energy option. At this stage of early industrial development the reliability assessment of WECs is a challenging task. In this paper existing reliability methods, namely Reliability Block diagrams, have been applied to a notional configuration. It was found that omnipresent lack of failure rate data makes rather crude adjustments of often generic data necessary which generally lead to rather unfavourable and highly uncertain results. Reliability data is either not available due to sparse field experience or is kept confidential, within different project developments to secure competitive advantages and intellectual property. In order to foster the progress of the marine energy industry, the reliability of devices must be demonstrated and improved. This requires a joint effort between industry stakeholders to collect, share and disseminate existing failure knowledge and future operational experience.Engineering and Physical Sciences Research Council (EPSRC) under the SUPERGEN Marine Doctoral Programm

Growing up with a mother with depression: an interpretative phenomenological analysis

The aim of this study was to explore the childhood experience of living with a parent with depression from a retrospective point of view. Five women between 39 and 47 years of age, who grew up with a mother with depression, were interviewed about their current perspectives on their childhood experiences. Interviews were semi-structured and the data were analyzed using interpretative phenomenological analysis. Data analysis led to a narrative organized in two parts. The first part (retrospective understanding of childhood experiences) reports on feelings of desolation contrasted to exceptional support, context-related dwelling on own experiences, and growing into a caring role as a way to keep standing. The second part (towards an integration of childhood experiences in adult realities) evidences ongoing processes of growing understanding of the situation at home, coping with own vulnerabilities, making the difference in their current family life and finding balance in the continued bond with the parents. This retrospective investigation of adults’ perspectives on their childhood experiences gave access to aspects of their experience that remain underexposed in research based on data from children and adolescents