Osseointegrated total knee replacement connected to a lower limb prosthesis: 4 cases

Background and purpose — Osseointegrated implants are an alternative for prosthetic attachment in individuals with amputation who are unable to wear a socket. However, the load transmitted through the osseointegrated fixation to the residual tibia and knee joint can be unbearable for those with transtibial amputation and knee arthritis. We report on the feasibility of combining total knee replacement (TKR) with an osseointegrated implant for prosthetic attachment. Patients and methods — We retrospectively reviewed all 4 cases (aged 38–77 years) of transtibial amputations managed with osseointegration and TKR in 2012–2014. The below-the-knee prosthesis was connected to the tibial base plate of a TKR, enabling the tibial residuum and knee joint to act as weight-sharing structures. A 2-stage procedure involved connecting a standard hinged TKR to custom-made implants and creation of a skin-implant interface. Clinical outcomes were assessed at baseline and after 1–3 years of follow-up using standard measures of health-related quality of life, ambulation, and activity level including the questionnaire for transfemoral amputees (Q-TFA) and the 6-minute walk test. Results — There were no major complications, and there was 1 case of superficial infection. All patients showed improved clinical outcomes, with a Q-TFA improvement range of 29–52 and a 6-minute walk test improvement range of 37–84 meters. Interpretation — It is possible to combine TKR with osseointegrated implants.

On the sufficient conditions for the equality of the unassignable polynomial and Davison's fixed polynomial of strongly connected systems

In this technical note, it is established that the unassignable polynomial defined for a not strongly connected decentralized control system is not equal to Davison's fixed polynomial. This leads to a "sufficient condition" for the equality of the unassignable polynomial and Davison's fixed polynomial for strongly connected systems.

Anisochrony of O-methylene protons of ethyl ester functions and structural factors in the connected chiral entities

(i) Incistrans pairs of cyclic 1,3-dicarboxylic acid ethyl esters thecis-foms exhibit higher O-methylene proton (HA, HB) anisochrony than thetrans-forms; (ii) anisochrony, easily observed in certain decalin-10-carboxylic ethyl esters, ‘disappears’ on one of the rings attaining the possibility of transforming into a ‘twist’ form; (iii) in certain pairs of chiralsecethyl esters and theirtert-methylated analogues anisochrony is higher in the latter, contrary to expectation, while, in certain others, the reverse is observed. Attempted explanations are based on assessments whether H A and H B are or are not in highly different magnetic environments in confomers regarded as preferred. This subsumes the possibility thatXYZC-CO2H A H B Me chiral ethyl acetates differ fromXYZC-CH A H B Me ethanes because intervention by the carboxyl group insulates the prochiral centre and allows anisotropic effects to gain somewhat in importance among mechanisms that discriminate between H A and H B so long as rotamerpopulation inequalities persist. Background information on why rotamer-population inequalities will always persist and on a heuristic that attempts to generalize the effects ofXYZ inXYZC - CU AUB V is provided. Possible effects when connectivity exists between a pair amongX, Y, Z or when specific interactions occur betweenV andX, Y orZ are considered. An interpretation in terms of ‘increasing conformational mobility’ has been suggested for the observed increase in the rate of temperature-dependence of O-methylene anisochrony down a series of chiral ethyl esters.

Grid-connected versus stand-alone energy systems for decentralized power-A review of literature

The decentralized power is characterised by generation of power nearer to the demand centers, focusing mainly on meeting local energy needs. A decentralized power system can function either in the presence of grid, where it can feed the surplus power generated to the grid, or as an independent/stand-alone isolated system exclusively meeting the local demands of remote locations. Further, decentralized power is also classified on the basis of type of energy resources used-non-renewable and renewable. These classifications along with a plethora of technological alternatives have made the whole prioritization process of decentralized power quite complicated for decision making. There is abundant literature, which has discussed various approaches that have been used to support decision making under such complex situations. We envisage that summarizing such literature and coming out with a review paper would greatly help the policy/decision makers and researchers in arriving at effective solutions. With such a felt need 102 articles were reviewed and features of several technological alternatives available for decentralized power, the studies on modeling and analysis of economic, environmental and technological asibilities of both grid-connected (GC) and stand-alone (SA) systems as decentralized power options are presented. (C) 2009 Elsevier Ltd. All rights reserved.

Recipe for success — Lessons learnt from using xAPI within the Connected Learning Analytics toolkit

An ongoing challenge for Learning Analytics research has been the scalable derivation of user interaction data from multiple technologies. The complexities associated with this challenge are increasing as educators embrace an ever growing number of social and content related technologies. The Experience API (xAPI) alongside the development of user specific record stores has been touted as a means to address this challenge, but a number of subtle considerations must be made when using xAPI in Learning Analytics. This paper provides a general overview to the complexities and challenges of using xAPI in a general systemic analytics solution - called the Connected Learning Analytics (CLA) toolkit. The importance of design is emphasised, as is the notion of common vocabularies and xAPI Recipes. Early decisions about vocabularies and structural relationships between statements can serve to either facilitate or handicap later analytics solutions. The CLA toolkit case study provides us with a way of examining both the strengths and the weaknesses of the current xAPI specification, and we conclude with a proposal for how xAPI might be improved by using JSON-LD to formalise Recipes in a machine readable form.

The Connected Learning Analytics toolkit

This demonstration introduces the Connected Learning Analytics (CLA) Toolkit. The CLA toolkit harvests data about student participation in specified learning activities across standard social media environments, and presents information about the nature and quality of the learning interactions.

Firm transformation: Advancing a Darwinian perspective

Purpose of the paper: The paper advocates a Darwinian explanation of the process of firm transformation. Existing, but generally opposing views related to the selection-adaptation debates are united to consider the dialogic nature of both approaches. It is argued that a Darwinian approach, as opposed to a neo-Darwinian or Lamarckian approach provides the means to scale the sides of a debate that has for too long divided scholars interested in firm and industry transformation. Approach: The paper addresses three specific issues to develop its Darwinian argument. Firstly, the various work of Geoff Hodgson that have for many years advanced Darwin's evolutionary ideas are used to argue the nature and application of Darwinism in the socio-economic domain. Secondly, the nature of what constitutes the elements of firm-environment interaction is considered to establish basic areas of focus through which the process of firm transformation is more understandable. Lastly, the construct absorptive capacity is likened to a mechanism of transmission through which the learning processes associated with the acquisition of favoured variations can be reconciled with the generic evolutionary processes of variation, selection, and retention. Findings: To understand the process of firm learning, the role of habits and routines must be outlined in specific detail. They cannot be assumed to perform interacting and replicating roles simultaneously. To do so, undermines the fundamental qualities of an evolutionary theory. What is the original/value of paper: The preliminary framework advanced takes us beyond the Darwinian - Lamarckian debate and provides elements of focus from which a greater understanding of the process of firm/industry transformation is possible.

An alternative view of small firm adaptation

Increasingly, small firms with a history tied to a specific geographic location are having their survival threatened by new and innovative web-based entrants. This paper considers the plight of such firms and proposes an alternative means to reflect on how they may or may not learn about such threats. Adopting an evolutionary perspective, the construct absorptive capacity is used to highlight the deficiencies of current market orientation theory to explain the process of firm learning. The conceptual model of evolutionary potential provides a framework through which both the firm and its owner/s' abilities to learn can be taken into account.

Small firm internet adoption: opportunities forgone, a journey not begun

This paper explores the endeavours of five small firms to develop web-based commerce capabilities within their existing operations. The focus is upon the strategic acquisition and exploitation of knowledge which underpins new value creating activates related to web-based commerce. A normative web-based commerce adoption model developed from a review of the extant literature related to electronic marketing, entrepreneurship, and the diffusion of new innovations was empirically tested. A multiple case study design enabled the exploration of contemporary marketing and entrepreneurship issues within the real life context of five small firms. The model aimed to emphasis best-practice adoption methods emphasizing the value of a firm's market orientation and entrepreneurial capabilities. A preliminary test of the model's theoretical contentions lent support to its overall focus, but found that the firm's existing learning capabilities were diminished during the adoption of web-based commerce, and that a lack of vision and prior knowledge produced sub-optimal adoption outcomes.

Small firm internet adoption: A market oriented approach

Fundamental to the development of new customer value offerings via web-based commerce is a small firm's ability to strategically acquire and exploit knowledge. The focus of this paper is the empirical testing of a normative web-based commerce adoption model developed from a review of the extant literature related to electronic marketing, the Internet and the diffusion of new innovations. A preliminary test of the model's theoretical contentions lent support to its overall focus, but found that the firm's existing learning capabilities were diminished during the adoption of web-based commerce. Consequently, sub-optimal adoption outcomes were associated with insufficient knowledge development.

An autecological interpretation of the firm and its environment

Explaining the survival and failure of firms is an important issue for researchers and managers of firms in society. Ecological approaches to the study of firms have existed for over 100 years, and have been increasingly popular during the past 40 years, especially since the pioneering works of Hannan and Freeman on one hand, and Aldrich on the other. This paper, in keeping with recent developments elsewhere in mainstream ecology outlines and positions the theoretical and philosophical foundations of an alternative ecological approach, autecology, that has not yet been formulated for the study of firms. The autecological approach affords the individual firm more autonomy in creating its own future evolutionary trajectory. The idea of an ecological complex is developed to provide clear focus on what is central to the application of autecology to the study of firms. The paper also considers several emergent research opportunities that highlight the potential value of employing an autecological approach to the study of firms.

Small firm internationalisation and the objective characteristics of managers: An importer's relationship marketing perspective

As a result of competitive pressures, firms are transitioning to international sourcing and initiating complex relationships with suppliers. Despite a lack of inward internationalisation research, there is progressive support for the importance of importing. Heavier focus has been placed on downstream efforts in past years, despite the fact that many factors affecting exporting also influence importing. For small and medium sized enterprises (SME), the psychic distance construct is especially important for internationalisation behaviour but there is little evidence on how perceptual psychic distance, that is the individual’s experiences, influences the buyer-seller relationship. This study draws on internationalisation process theory and commitment-trust theory, in an effort to describe the relationship between objective characteristics (i.e. language, cultural background, education and international experience) and relationship marketing (trust and commitment). The study utilises a holistic, multiple case study design to gain a deeper understanding of the inherent complexities of the relationships in dyads and how objective characteristics, which reduce psychic distance, can facilitate trust and commitment development between importers and exporters.

Organizational competencies and dynamic Accounting Information System capability: Impact on AIS processes and firm performance

Accounting information systems (AIS) capture and process accounting data and provide valuable information for decision-makers. However, in a rapidly changing environment, continual management of the AIS is necessary for organizations to optimise performance outcomes. We suggest that building a dynamic AIS capability enables accounting process and organizational performance. Using the dynamic capabilities framework (Teece 2007) we propose that a dynamic AIS capability can be developed through the synergy of three competencies: a flexible AIS, having a complementary business intelligence system and accounting professionals with IT technical competency. Using survey data, we find evidence of a positive association between a dynamic AIS capability, accounting process performance, and overall firm performance. The results suggest that developing a dynamic AIS resource can add value to an organization. This study provides guidance for organizations looking to leverage the performance outcomes of their AIS environment.

Following fashion: Visible progressiveness and the social construction of firm value

A central tenet underlying studies on management fashions is that the diffusion of novel forms, models and techniques is driven by an institutional norm of progress, which is the societal expectation that managers will continuously use 'new and improved' management practices. We add to the literature on management fashions by arguing that, if the display of progressiveness in the manner of managing and organizing is expected of organizations, firms that are visibly progressive would be evaluated more positively by organizational audiences following this institutional prescription. Using article counts of co-occurrences of firms and various fashionable management practices in Wall Street Journal, we hypothesize positive effects of such associations on security analysts' evaluations of these firms. Results support this hypothesis. Our study enriches the management fashion literature by highlighting the consequential relevance of organizational adherence to the norm of progress.

On the Structure of Contractible Edges in k-connected Partial k-trees

Contraction of an edge e merges its end points into a new single vertex, and each neighbor of one of the end points of e is a neighbor of the new vertex. An edge in a k-connected graph is contractible if its contraction does not result in a graph with lesser connectivity; otherwise the edge is called non-contractible. In this paper, we present results on the structure of contractible edges in k-trees and k-connected partial k-trees. Firstly, we show that an edge e in a k-tree is contractible if and only if e belongs to exactly one (k + 1) clique. We use this characterization to show that the graph formed by contractible edges is a 2-connected graph. We also show that there are at least |V(G)| + k - 2 contractible edges in a k-tree. Secondly, we show that if an edge e in a partial k-tree is contractible then e is contractible in any k-tree which contains the partial k-tree as an edge subgraph. We also construct a class of contraction critical 2k-connected partial 2k-trees.