Micro-Mechanical Approaches for the Hierarchical Modeling of Soft Biological Tissues

Load-bearing soft tissues are abundant throughout the human body, including such diverse examples as skin, cornea, tendons, and blood vessels. The mechanical characterization of these tissues is important for applications such as tissue engineering, disease state pathology, and medical device/patient interface modeling. The mechanical properties of soft tissues arise from the underlying collagen microstructure, which varies across the body depending on tissue function. Such specialized microstructures are thought to arise in part from the ability of soft tissues to self-adapt to the mechanical environment by a process known as growth and remodeling. Growth and remodeling is a normal part of tissue development and maintenance; however, it is suspected that an imbalance in the process may contribute to disease states such as osteoarthritis and glaucoma. Though growth and remodeling are well documented, the mechanisms driving the process are not well understood. This work develops a hierarchical, structure-based modeling approach for planar collagenous tissues based on the underlying collagen microstructure. The approach was applied both to characterize human skin mechanics for prosthetic/residual limb interface modeling, and to simulate potential fiber-level mechanisms of the growth and remodeling process. The nonlinear, anisotropic properties of human skin tissues were measured using full-field inflation testing, and a novel analytical method was developed to fit constitutive model parameters to the inflation test data while accounting for bending stresses. Two different anisotropic constitutive models were considered: a fully integrated distributed fiber model, and a more computationally efficient generalized structure tensor model. Finite element analysis was used to show that only the fully integrated distributed fiber model could reproduce the experimentally measured anisotropy of skin tissue. To investigate potential mechanisms of growth and remodeling, the fully integrated model was extended to incorporate a micro-mechanical description of the collagen fibers. This enabled the prescription of fiber-level evolution equations for strain-protected enzymatic degradation and constant collagen deposition as potential mechanisms of the growth and remodeling process. The degradation model was calibrated to fibril-level experiments and used to predict tissue-level experiments for model validation. Strain homeostasis was achieved when the degradation model was paired with constant collagen deposition, supporting these two mechanisms as potential mechanisms of the growth and remodeling process

Employee Attributions of the Why of HR Practices: Their Effects on Employee Attitudes and Behaviors, and Customer Satisfaction

The construct of Human Resource (HR) Attributions is introduced. We argue that the attributions that employees make about the reasons why management adopts the HR practices that it does have consequences for their attitudes and behaviors, and ultimately, unit performance. Drawing on the strategic HR literature, we propose a typology of five HR-Attribution dimensions. Utilizing data collected from a service firm, we show that employees make varying attributions for the same HR practices, and that these attributions are differentially associated with commitment and satisfaction. In turn, we show that these attitudes become shared within units and that they are related to unit-level organizational citizenship behaviors and customer satisfaction. Findings and implications are discussed

Perspectives on safety culture

Overviewing selected elements from the literature, this paper locates the notion of safety culture within its parent concept of organisational culture. A distinction is drawn between functionalist and interpretive perspectives on organisational culture. The terms ‘culture’ and ‘climate’ are clarified as they are typically applied to organisations and to safety. A contrast is drawn between strategic top down and data-driven bottom up approaches to human factors as an illustrative aspect of safety. A safety case study is used to illustrate two measurement approaches. Key issues for future study include valid measurement of safety culture and developing methods to adequately represent mechanisms through which safety culture might influence, and be influenced by, other safety factors

Spectral switching control of ultrafast pulses in dual core photonic crystal fibre

The work presented in this paper is a study of an all-optical narrow-band switch in extended spectral area by dual core photonic crystal fibre expressing nonlinear coupler performance. The investigation is focused on the nonlinear propagation of femtosecond pulses in the near infrared spectral region at up to 50 kW peak power which induces spectral broadening through almost two octaves. The mutual effect of nonlinear spectral transformation and field redistribution between the two fibre cores is analyzed by both theoretical and experimental approaches. The simulation of the nonlinear propagation is based on coupled generalized nonlinear Schrödinger equations. A modified numerical model utilizing split-step Fourier method was adapted for dual core fibres. The complex experimental study was accomplished for various input settings such as polarization, intensity and selective coupling into each core and the selective detection of spectra from each core. The presented work encompasses promising results obtained regarding a spectral intensity switch between the two output channels by input intensity or polarization change in the S-band of optical communication systems

Interracial Public-Police Contact: Relationships with Police Officers’ Racial and Work-Related Attitudes and Behavior

In a sample of Flemish police officers (N = 172), we examined whether interracial public-police contact is associated with police officers’ racial and workrelated attitudes and self-reported behavior. Complementing previous studies, it was revealed that interracial contact (both positive and negative) is related to prejudiced behavior toward immigrants via the mediating role of racial attitudes. Moreover, intergroup contact was also shown to be related to police officers’ organizational citizenship behavior toward colleagues and superiors via their perceptions of organizational fairness. In the discussion section we elaborate on the severe impact of negative contact as well as the applied consequences of our findings within police organizations

The Relationship Between HR Practices and Firm Performance: Examining Causal Order

Significant research attention has been devoted to examining the relationship between HR practices and firm performance, and the research support has assumed HR as the causal variable. Using data from 45 business units (with 62 data points), this study examines how measures of HR practices correlate with past, concurrent, and future operational performance measures. The results indicate that correlations with performance measures at all three times are both high and invariant, and that controlling for past or concurrent performance virtually eliminates the correlation of HR with future performance. Implications are discussed

A study protocol to investigate the management of depression and challenging behaviors associated with dementia in aged care settings

Background:&nbsp;The high occurrence and under-treatment of clinical depression and behavioral and psychological symptoms of dementia (BPSD) within aged care settings is concerning, yet training programs aimed at improving the detection and management of these problems have generally been ineffective. This article presents a study protocol to evaluate a training intervention for facility managers/registered nurses working in aged care facilities that focuses on organisational processes and culture as well as knowledge, skills and self-efficacy. Methods. A Randomised Control Trial (RCT) will be implemented across 18 aged care facilities (divided into three conditions). Participants will be senior registered nurses and personal care attendants employed in the aged care facility. The first condition will receive the training program (Staff as Change Agents - Enhancing and Sustaining Mental Health in Aged Care), the second condition will receive the training program and clinical support, and the third condition will receive no intervention. Results: Pre-, post-, 6-month and 12-month follow-up measures of staff and residents will be used to demonstrate how upskilling clinical leaders using our transformational training approach, as well as the use of a structured screening, referral and monitoring protocol, can address the mental health needs of older people in residential care. Conclusions: The expected outcome of this study is the validation of an evidence-based training program to improve the management of depression and BPSD among older people in residential care settings by establishing routine practices related to mental health. This relatively brief but highly focussed training package will be readily rolled out to a larger number of residential care facilities at a relatively low cost.</div

Team climate, climate strength and team performance: a longitudinal study

We tested the hypothesis that the relationship between team climate and team performance is moderated by climate strength. The study sample was composed of 155 bank branches, and a two-wave panel design was implemented. We measured four team climate facets (support, innovation, goal achievement and enabling formalization). We obtained two subjective indicators of team performance (ratings provided by team members and by team managers) and a financial indicator of team performance. Seven out of the 12 interaction effects tested were statistically significant and showed the expected sign. When financial team performance was the criterion, only the interaction term was significant. This suggests that only strong climates are related to financial team performance over time

A look back to move ahead: New directions for research on proactive performance and other discretionary work behaviours

Over the last two decades, the multi-dimensional notion of job performance has been fully brought to life. The differentiation between core task performance and various aspects of discretionary work behaviour is now commonly applied. A multitude of empirical studies, enhancing our knowledge of the antecedents and consequences of the different performance aspects, have recently been summarised through various meta-analyses. We use this as an occasion for taking stock in order to identify new areas of theorising and empirical research. Focusing in particular on proactive performance aspects, the present paper identifies three themes that could inspire new research and model development. We suggest taking a new approach to the treatment of time in order to account for the dynamic nature of performance on the one hand, and to consider life-span changes on the other, developing comprehensive models on proactivity-enhancing interventions, and more strongly incorporating a cross- cultural perspective

Do organizational climate and competitive strategy moderate the relationship between human resource management and productivity?

This study examined whether the effectiveness of human resource management (HRM)practices is contingent on organizational climate and competitive strategy The concepts of internol and external fit suggest that the positive relationship between HRM and subsequent productivity will be stronger for firms with a positive organizational climate and for firms using differentiation strategies. Resource allocation theories of motivation, on the other hand, predict that the relationship between HRM and productivity will be stronger for firms with a poor climate because employees working in these firms should have the greatest amount of spare capacity. The results supported the resource allocation argument