Medical device development: the challenge for ergonomics

High quality, well-designed medical devices are necessary to provide safe and effective clinical care for patients as well as to ensure the health and safety of professional and lay device users. Capturing the user requirements of users and incorporating these into design is an essential component of this. The field of ergonomics has an opportunity to assist, not only with this area, but also to encourage a more general consideration of the user during medical device development. A review of the literature on methods for assessing user requirements in engineering and ergonomics found that little published work exists on the ergonomic aspects of medical device development. In particular there is little advice available to developers on which issues to consider during design and development or recommendations for good practice in terms of the methods and approaches needed to capture the full range of user requirements. The Multidisciplinary Assessment of Technology Centre for Health care (MATCH) is a research collaboration that is working in conjunction with industrial collaborators to apply ergonomics methods to real case study projects with the ultimate aim of producing an industry-focused guide to applying ergonomics principles in medical device development.     

Empowering followers in virtual teams: Guiding principles from theory and practice

Effective leadership requires relationship skills such as – problem solving conflict management, motivation, communication, and listening [Yukl, G. A. (1998). Leadership in organizations. Upper Saddle River, NJ: Prentice Hall]. Arguably, nothing is more important to a leader than the skills involved in communicating one’s intent to followers, for it is only through effectively transmitting intent that followers may understand and then execute the goals of the team and leader. The modern work-world is dominated by computer-mediated communication, and this communication is the bread and butter of virtual teams; however, simple transmission of information from point A to point B is not enough – the virtual environment presents significant challenges to effective communication. In this paper we review issues related to virtual teams and developments in multimodal displays that allow teams to communicate effectively via single or multiple modalities (e.g., visual, auditory, tactile). This discussion is grounded in guiding principles for design and use of information displays that were identified and culled based on multiple review criteria from an extensive review of the literature. We present an applied example of the utility of these guiding principles for multimodal display design, in the context of communicating a leader’s presence to virtual followers via commander’s intent.     

Single-period inventory model with a delayed incentive option for selling excess inventory

The single‐period problem (SPP) is to find the order quantity which maximizes the expected profit in a single period probabilistic demand framework. We extend the SPP to a case where a retailer uses delayed incentives in the form of cash mail‐in rebates to sell remaining inventory that did not sell at the regular price. The advantage of cash mail‐in rebates is that not all consumers will redeem them. We address three cases: (1) rebate value is predetermined and the order quantity is a decision variable; (2) order quantity is a decision variable and rebate value is set to the value needed to sell all excess inventory, and (3) order quantity is a decision variable and the rebate may be used to sell part of or all excess inventory. In the third case, any inventory remaining after the rebate offer is salvaged at reduced price. We provide analytical solutions for uniform and exponential demand distributions. In all cases, rebates can lead to significant increases in expected profit. We first maximize the expected profit. We then maximize the probability of achieving a target profit and show that the use of rebates can lead to a substantial increase in that probability.     

The effect of a flood pulse on the water column of western Lake Superior,USA

On June 19 and 20, 2012, western Lake Superior was impacted by a “mega-rain event” that raised lake levels by 8 to 10 cm. Within the flood plume on June 21, 2012, total suspended solids, total phosphorus, and soluble reactive phosphorus concentrations were elevated, with measurements of 87 mg/L, > 100 μg/L, and 5.8 μg/L, respectively. Despite the initially high phosphorus loadings, little impact was seen on water column particulate chlorophyll content, which remained in the range 0.7–1.9 μg/L, in the weeks to months following the flood. Both total phosphorus and soluble reactive phosphorus levels tracked those of total suspended solids, returning to background levels within two weeks. However, the availability of photosynthetically available radiation (PAR) was impacted for a month after the flood event, due mainly to colored dissolved organic matter that remained in the surface layer of the stratified lake water column. It appears that the mismatch in timing of nutrient and light availability acted as a check on phytoplankton biomass production in the flood-impacted portion of the lake.     

Why situational method engineering is useful to information systems development

Effective methods and methodologies for building information systems (IS) remain crucial to building successful IS. This paper investigates the use of situational method engineering for IS development (ISD) projects in a professional bureaucracy. This specialist organization methodology (SOM) is built starting with the philosophy of ISD moving through to flexible, amethodical implementation methods, a proposed instance of situational method engineering that is targeted towards professional bureaucracies. An in‐depth philosophical discussion of the ontological, epistemological, research methodological and ethical underpinnings of SOM are outlined, in addition to its limitations, to develop the building blocks of a methodology to implement within a professional bureaucracy organization ISD scenario. Amethodical ISD will be introduced as the appropriate way to implement this developed methodology to build a successful IS. The contribution of this paper is to detail how to develop a philosophically consistent methodology for a specific organizational environment (in this case, using the specific organizational example of a professional bureaucracy) that, when combined with developers and tools, can create a method to be applied to build an IS that has a greater possibility of successful organizational adoption than an IS built using a method devised using more common IS method engineering approaches.     

Statistical modelling of communities and ecosystems using the LAMDA software tool

Understanding species interactions is critical to discovering community dynamics. Recently, statistical methods for estimating species interaction strengths from time series data have been developed based on multivariate auto-regressive first-order, or MAR(1), models. However, the complex coding required presents a substantial barrier for most ecologists. We have developed LAMBDA, a software program that allows users to easily fit MAR(1) models to multi-species time series data. The LAMBDA package covers: data input and transformation, selection of the interactions to include via a search algorithm and model selection, estimation of interaction parameters via conditional least squares (CLS) regression or two different maximum-likelihood (ML) algorithms, estimation of confidence intervals via bootstrapping, and computation of community stability properties using the estimated model. We describe performance tests on the variability of estimates, computation speed, and CLS versus ML estimation using simulated data.     

Accumulation of heavy metals in the physical and biological systems of Lake Koka,Ethiopia: Implications for potential health risks

Lake Koka has several important socioeconomic uses, hydroelectric power generation, domestic water supply, irrigation, recreation and fishery. It is currently under serious threat, however, because of point and nonpoint pollution inputs. The objective of the present study was to examine the concentration of heavy metals (Mn, Cr, Pb, Zn, Cu, Ni and Cd) and their bioaccumulation, and biomagnification factors along the lake's food chain in order to assess the potential human and ecological health risks. Water, sediment and plankton samples were collected from seven sampling sites and fishes were purchased on site from fishers. The analyses were performed using a graphite furnance atomic absorption spectrophotometer. Heavy metals levels in the sediment samples were ranked in the order of Mn > Cr > Pb > Zn > Cu > Ni > Cd. Similarly, the metal concentration in the fish muscles was Cr > Cu > Pb > Cd. The sediment bioaccumulation factor (<1) and water bioaccumulation factor (>1) for Cd, Pb and Cr indicated the lake water exhibited higher concentrations than the sediment. In parallel, the Cr biomagnification factor for zooplankton, catfish, Nile tilapia and common carp was 1.63, 1.18, 1.36 and 2.28, respectively. The Cr concentrations at the Modjo (or Mojo) Upstream, Modjo Downstream and Kentare sites, and the Pb concentrations at riverine sites were above the permissible limits established by the World Health Organization. Cr ranked as fish species > zooplankton > phytoplankton, being above the permissible limits in catfish, Nile tilapia and common carp. Generally, the weekly intake estimates were considerably lower than the tolerable human intake values provided by WHO and others. However, Cr biomagnified along the trophic levels ultimately reaching the top consumers, with Cr (VI) being carcinogenic. The lake is a major fishery source, indicating care must be taken in regard to the weekly intake of the fishes, particularly common carp.     

Escherichia coli toxin and attachment genes in sand at Great Lakes recreational beaches

The United States Environmental Protection Agency recommends density thresholds for the fecal indicator organism Escherichia coli in order to ensure the safety of recreational waters. A number of studies published over the past ten years indicate that E. coli is encountered frequently in sand at recreational beaches. While a majority of the sand-associated E. coli may be commensal or environmental strains, the potential for pathogenic strains of E. coli to be present exists. Therefore, the aim of this study was to assess the presence of attachment and virulence genes associated with enteropathogenic and enterohemorrhagic strains of E. coli (EPEC and EHEC) in populations of E. coli recovered from swash zone sand from seven recreational beaches along Lake Huron and Lake St. Clair in eastern Michigan, USA. Genes coding for attachment proteins in EPEC and EHEC were very prevalent in sand E. coli, but genes coding for toxin genes were uncommon. The paucity of genes associated with E. coli toxins suggests that the EPEC and EHEC pathotypes are not common in sand; however, the high prevalence of genes associated with attachment in E. coli pathotypes suggests that these genes are being retained within the beach sand E. coli population.     

Engagement in digital entertainment games: A systematic review

Since their introduction over 40 years ago, digital entertainment games have become one of the most popular leisure activities globally. While digital games clearly provide highly engaging activities, the nature of this engagement is not well understood. The current study aims to advance our understanding by reporting a systematic review of recent literature addressing engagement in computer games. The papers in the review comprise a sub-sample of papers relating to engagement in digital games that was selected from a broader literature search carried out on the outcomes and impacts of playing computer games. A diverse range of studies was identified that examined varied aspects of engagement in games including subjective experiences while playing games, the physiological concomitants of these experiences, motives for playing games, game usage and time spent playing games and the impact of playing on life satisfaction. A narrative review was carried out to capture these diverse aspects of engagement and to develop a more coherent understanding of engagement in computer games.     

SOMAR: A SOcial Mobile Activity Recommender

A 2010 survey (Nielsen) showed that 22.7% of the time spent on the Internet is on a social network. Moreover, there is an increasing demand to access social networks by mobile phones, i.e., around 30% globally. Social networking has become a reality, and it generates an incredible amount of information that is sometimes difficult for users to process, especially from mobile phones. Several links, activities, and recommendations are proposed by networked friends every hour, which together are nearly impossible to manage. There is a need to filter and make accessible such information to users, which is the motivation behind developing a mobile recommender that exploits social network information. Thus, in this paper, we propose the design and the implementation of a SOcial Mobile Activity Recommender (SOMAR) that can integrate Facebook social network mobile data and sensor data to propose activities to the user (e.g., concert or computer science seminar). The recommendations are completely calculated in situ in the mobile device with an embedded data mining component. We analyze how to compute and update the social graph in case of changes in social relationships or user context. The paper also presents a case study to analyze the performance of the method.