Risedronate in adults with osteogenesis imperfecta type I: Increased bone mineral density and decreased bone turnover, but high fracture rate persists

Summary Bisphosphonates can increase bone mineral density (BMD) in children with osteogenesis imperfecta (OI). In this study of adults with OI type I, risedronate increased BMD at lumbar spine (but not total hip) and decreased bone turnover. However, the fracture rate in these patients remained high. Introduction Intravenous bisphosphonates given to children with OI can increase BMD and reduce fracture incidence. Oral and/or intravenous bisphosphonates may have similar effects in adults with OI. We completed an observational study of the effect of risedronate in adults with OI type I. Methods Thirty-two adults (mean age, 39 years) with OI type I were treated with risedronate (total dose, 35 mg weekly) for 24 months. Primary outcome measures were BMD changes at lumbar spine (LS) and total hip (TH). Secondary outcome measures were fracture incidence, bone pain, and change in bone turnover markers (serum procollagen type I aminopropeptide (P1NP) and bone ALP). A meta-analysis of published studies of oral bisphosphonates in adults and children with OI was performed. Results Twenty-seven participants (ten males and seventeen females) completed the study. BMD increased at LS by 3.9% (0.815 vs. 0.846 g/cm 2, p=0.007; mean Z-score, -1.93 vs. -1.58, p=0.002), with no significant change at TH. P1NP fell by 37% (p=0.00041), with no significant change in bone ALP (p=0.15). Bone pain did not change significantly (p=0.6). Fracture incidence remained high, with 25 clinical fractures and 10 major fractures in fourteen participants (0.18 major fractures per person per year), with historical data of 0.12 fractures per person per year. The meta-analysis did not demonstrate a significant difference in fracture incidence in patients with OI treated with oral bisphosphonates. Conclusions Risedronate in adults with OI type I results in modest but significant increases in BMD at LS, and decreased bone turnover. However, this may be insufficient to make a clinically significant difference to fracture incidence.

Genetic determinants of bone density and fracture risk: State of the art and future directions

Context: Osteoporosis is a common, highly heritable condition that causes substantial morbidity and mortality, the etiopathogenesis of which is poorly understood. Genetic studies are making increasingly rapid progress in identifying the genes involved. Evidence Acquisition and Synthesis: In this review, we will summarize the current understanding of the genetics of osteoporosis based on publications from PubMed from the year 1987 onward. Conclusions: Most genes involved in osteoporosis identified to date encode components of known pathways involved in bone synthesis or resorption, but as the field progresses, new pathways are being identified. Only a small proportion of the total genetic variation involved in osteoporosis has been identified, and new approaches will be required to identify most of the remaining genes.

Genome-wide meta-analysis identifies 56 bone mineral density loci and reveals 14 loci associated with risk of fracture

Bone mineral density (BMD) is the most widely used predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P < 5 × 10−8). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P < 5 × 10−4, Bonferroni corrected), of which six reached P < 5 × 10−8, including at 18p11.21 (FAM210A), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.

Crash risk perception of sleepy driving and its comparisons with drink driving and speeding: Which behavior is perceived as the riskiest?

- Objective Driver sleepiness is a major crash risk factor, but may be under-recognized as a risky driving behavior. Sleepy driving is usually rated as less of a road safety issue than more well-known risky driving behaviors, such as drink driving and speeding. The objective of this study was to compare perception of crash risk of sleepy driving, drink driving, and speeding. - Methods In total, 300 Australian drivers completed a questionnaire that assessed crash risk perceptions for sleepy driving, drink driving, and speeding. Additionally, the participants perception of crash risk was assessed for five different contextual scenarios that included different levels of sleepiness (low, high), driving duration (short, long), and time of day/circadian influences (afternoon, night-time) of driving. - Results The analysis confirmed that sleepy driving was considered a risky driving behavior, but not as risky as high levels of speeding (p < .05). Yet, the risk of crashing at 4 am was considered as equally risky as low levels of speeding (10 km over the limit). The comparisons of the contextual scenarios revealed driving scenarios that would arguably be perceived as quite risky due to time of day/circadian influences were not reported as high risk. - Conclusions The results suggest a lack of awareness or appreciation of circadian rhythm functioning, particularly the descending phase of circadian rhythm that promotes increased sleepiness in the afternoon and during the early hours of the morning. Yet, the results suggested an appreciation of the danger associated with long distance driving and driver sleepiness. Further efforts are required to improve the community’s awareness of the impairing effects from sleepiness and in particular, knowledge regarding the human circadian rhythm and the increased sleep propensity during the circadian nadir.

Study on the elastic-plastic behavior of a porous hierarchical bioscaffold used for bone regeneration

A perfectly plastic von Mises model is proposed to study the elastic-plastic behavior of a porous hierarchical scaffold used for bone regeneration. The proposed constitutive model is implemented in a finite element (FE) routine to obtain the stress-strain relationship of a uniaxially loaded cube of the scaffold, whose constituent is considered to be composed of cortical bone. The results agree well with experimental data for uniaxial loading case of a cancellous bone. We find that the unhomogenized stress distribution results in different mechanical properties from but still comparable to our previous theory. The scaffold is a promising candidate for bone regeneration.

Risk assessment of wandering behavior in mild dementia

Objective This prospective longitudinal study aims to determine the risk factors of wandering-related adverse consequences in community-dwelling persons with mild dementia. These adverse consequences include negative outcomes of wandering (falls, fractures, and injuries) and eloping behavior. Methods We recruited 143 dyads of persons with mild dementia and their caregivers from a veteran's hospital and memory clinic in Florida. Wandering-related adverse consequences were measured using the Revised Algase Wandering Scale – Community Version. Variables such as personality (Big Five Inventory), behavioral response to stress, gait, and balance (Tinetti Gait and Balance), wayfinding ability (Wayfinding Effectiveness Scale), and neurocognitive abilities (attention, cognition, memory, language/verbal skills, and executive functioning) were also measured. Bivariate and logistic regression analyses were performed to assess the predictors of these wandering-related adverse consequences. Results A total of 49% of the study participants had falls, fractures, and injuries due to wandering behavior, and 43.7% demonstrated eloping behaviors. Persistent walking (OR = 2.6) and poor gait (OR = 0.9) were significant predictors of negative outcomes of wandering, while persistent walking (OR = 13.2) and passivity (OR = 2.55) predicted eloping behavior. However, there were no correlations between wandering-related adverse consequences and participants' characteristics (age, gender, race, ethnicity, and education), health status (Charlson comorbidity index), or neurocognitive abilities. Conclusion Our results highlight the importance of identifying at-risk individuals so that effective interventions can be developed to reduce or prevent the adverse consequences of wandering.

Vineland Adaptive Behavior Scales - II profile of young children with Autism Spectrum Disorder

Adaptive behaviour is a crucial area of assessment for individuals with Autism Spectrum Disorder (ASD). This study examined the adaptive behaviour profile of 77 young children with ASD using the Vineland-II, and analysed factors associated with adaptive functioning. Consistent with previous research with the original Vineland a distinct autism profile of Vineland-II age equivalent scores, but not standard scores, was found. Highest scores were in motor skills and lowest scores were in socialisation. The addition of the Autism Diagnostic Observation Schedule (ADOS) calibrated severity score did not contribute significant variance to Vineland-II scores beyond that accounted for by age and nonverbal ability. Limitations, future directions, and implications are discussed.

An analysis of theories of search and search behavior

Theories of search and search behavior can be used to glean insights and generate hypotheses about how people interact with retrieval systems. This paper examines three such theories, the long standing Information Foraging Theory, along with the more recently proposed Search Economic Theory and the Interactive Probability Ranking Principle. Our goal is to develop a model for ad-hoc topic retrieval using each approach, all within a common framework, in order to (1) determine what predictions each approach makes about search behavior, and (2) show the relationships, equivalences and differences between the approaches. While each approach takes a different perspective on modeling searcher interactions, we show that under certain assumptions, they lead to similar hypotheses regarding search behavior. Moreover, we show that the models are complementary to each other, but operate at different levels (i.e., sessions, patches and situations). We further show how the differences between the approaches lead to new insights into the theories and new models. This contribution will not only lead to further theoretical developments, but also enables practitioners to employ one of the three equivalent models depending on the data available.

Analyzing hysteresis behavior of capacitance-voltage characteristics of IZO/C₆₀/pentacene/Au diodes with a hole-transport electron-blocking polyterpenol layer by electric-field-induced optical second-harmonic generation measurement

By using electric-field-induced optical second-harmonic generation (EFISHG) measurement, we analyzed hysteresis behavior of capacitance-voltage (C-V) characteristics of IZO/polyterpenol (PT)/C₆₀/pentacene/Au diodes, where PT layer is actively working as a hole-transport electron-blocking layer. The EFISHG measurement verified the presence of interface accumulated charges in the diodes, and showed that a space charge electric field from accumulated excess electrons (holes) that remain at the PT/C₆₀ (C₆₀/pentacene) interface is responsible for the hysteresis loop observed in the C-V characteristics.

Relationships between daily affect and pro-environmental behavior at work: The moderating role of pro-environmental attitude

Research in organizational psychology has increasingly focused on understanding the determinants of "green" employee behavior. The present study used a daily diary design to investigate relationships between employees' daily affect, pro-environmental attitude, as well as daily task-related pro-environmental behavior (i.e., the extent to which employees complete required work tasks in environmentally friendly ways), and daily proactive pro-environmental behavior (i.e., the extent to which employees show personal initiative when acting in environmentally friendly ways at work). Fifty-six employees working in small businesses completed a baseline survey and two daily surveys over ten workdays. Daily unactivated positive affect and pro-environmental attitude positively predicted daily task-related pro-environmental behavior. In addition, daily activated positive affect positively predicted daily proactive pro-environmental behavior among employees with a less positive pro-environmental attitude but not among employees with a more positive pro-environmental attitude. These findings suggest that fostering pro-environmental attitudes and, to some extent, positive affect among employees could help organizations to promote pro-environmental behavior in the workplace.

On the importance of pro-environmental organizational climate for employee green behavior

In their call to action, Ones and Dilchert(2012) discuss several possible individual and some contextual determinants of employee green behavior that await examination by industrial and organizational I–O) psychologists. Although these authors briefly mentioned organizational climate, specifically ethical climate, as a potentially relevant predictor of green behaviors, they mostly emphasized the role of individual difference characteristics and traditional job performance determinants such as knowledge, skills, abilities, and other person factors (KSAOs).

Employee green behavior: A theoretical framework, multilevel review, and future research agenda

We propose a conceptual model based on person–environment interaction, job performance, and motivational theories to structure a multilevel review of the employee green behavior (EGB) literature and agenda for future research. We differentiate between required EGB prescribed by the organization and voluntary EGB performed at the employees’ discretion. The review investigates institutional-, organizational-, leader-, team-, and employee-level antecedents and outcomes of EGB and factors that mediate and moderate these relationships. We offer suggestions to facilitate the development of the field, and call for future research to adopt a multilevel perspective and to investigate the outcomes of EGB.

Experimental and numerical investigation of strain-rate-dependent behavior of kangaroo shoulder cartilage

This thesis introduces a new animal model, kangaroo, to biomechanical investigations of shoulder cartilage research. It examines the effect of cartilage structure and constituents on tissue behavior and its adaptation to mechanical loading. In doing so, the study explains the relationship of tissue's functional behaviors to its structure and constituents which has important implications for tissue engineering strategies catering joint specific cartilage tissue generation.

Impact of malnutrition on 12-month mortality following acute hip fracture

Background Studies investigating the relationship between malnutrition and post-discharge mortality following acute hip fracture yield conflicting results. This study aimed to determine whether malnutrition independently predicted 12-month post-fracture mortality after adjusting for clinically relevant covariates. Methods An ethics approved, prospective, consecutive audit was undertaken for all surgically treated hip fracture inpatients admitted to a dedicated orthogeriatric unit (November 2010–October 2011). The 12-month mortality data were obtained by a dual search of the mortality registry and Queensland Health database. Malnutrition was evaluated using the Subjective Global Assessment. Demographic (age, gender, admission residence) and clinical covariates included fracture type, time to surgery, anaesthesia type, type of surgery, post-surgery time to mobilize and post-operative complications (delirium, pulmonary and deep vein thrombosis, cardiac complications, infections). The Charlson Comorbidity Index was retrospectively applied. All diagnoses were confirmed by the treating orthogeriatrician. Results A total of 322 of 346 patients were available for audit. Increased age (P = 0.004), admission from residential care (P < 0.001), Charlson Comorbidity Index (P = 0.007), malnutrition (P < 0.001), time to mobilize >48 h (P < 0.001), delirium (P = 0.003), pulmonary embolism (P = 0.029) and cardiovascular complication (P = 0.04) were associated with 12-month mortality. Logistic regression analysis demonstrated that malnutrition (odds ratio (OR) 2.4 (95% confidence interval (CI) 1.3–4.7, P = 0.007)), in addition to admission from residential care (OR 2.6 (95% CI 1.3–5.3, P = 0.005)) and pulmonary embolism (OR 11.0 (95% CI 1.5–78.7, P = 0.017)), independently predicted 12-month mortality. Conclusions Findings substantiate malnutrition as an independent predictor of 12-month mortality in a representative sample of hip fracture inpatients. Effective strategies to identify and treat malnutrition in hip fracture should be prioritized.

Gap acceptance behavior of mobile phone distracted drivers at roundabouts

While mobile phones have become ubiquitous in modern society, the use of mobile phones while driving is increasing at an alarming rate despite the associated crash risks. A significant safety concern is that driving while distracted by a mobile phone is more prevalent among young drivers, a less experienced driving cohort with elevated crash risk. The objective of this study was to examine the gap acceptance behavior of distracted young drivers at roundabouts. The CARRS-Q Advanced Driving Simulator was used to test participants on a simulated gap acceptance scenario at roundabouts. Conflicting traffic from the right approach of a four-legged roundabout were programmed to have a series of vehicles having the gaps between them proportionately increased from two to six seconds. Thirty-two licensed young drivers drove the simulator under three phone conditions: baseline (no phone conversation), hands-free and handheld phone conversations. Results show that distracted drivers started responding to the gap acceptance scenario at a distance closer to the roundabout and approached the roundabout at slower speeds. They also decelerated at faster rates to reduce their speeds prior to gap acceptance compared to non-distracted drivers. Although accepted gap sizes were not significantly different across phone conditions, differences in the safety margins at various gap sizes—measured by Post Encroachment Time (PET) between the driven vehicle and the conflicting vehicle—were statistically significant across phone conditions. PETs for distracted drivers were smaller across different gap sizes, suggesting a lower safety margin taken by distracted drivers compared to non-distracted drivers. The results aid in understanding how cognitive distraction resulting from mobile phone conversations while driving influences driving behavior during gap acceptance at roundabouts.