Hamstring strain injuries : factors that lead to injury and re-injury

Hamstring strain injuries (HSIs) are common in a number of sports and incidence rates have not declined in recent times. Additionally, the high rate of recurrent injuries suggests that our current understanding of HSI and re-injury risk is incomplete. Whilst the multifactoral nature of HSIs is agreed upon by many, often individual risk factors and/or causes of injury are examined in isolation. This review aims to bring together the causes, risk factors and interventions associated with HSIs to better understand why HSIs are so prevalent. Running is often identified as the primary activity type for HSIs and given the high eccentric forces and moderate muscle strain placed on the hamstrings during running these factors are considered to be part of the aetiology of HSIs. However, the exact causes of HSIs remain unknown and whilst eccentric contraction and muscle strain purportedly play a role, accumulated muscle damage and/or a single injurious event may also contribute. Potentially, all of these factors interact to varying degrees depending on the injurious activity type (i.e. running, kicking). Furthermore, anatomical factors, such as the biarticular organization, the dual innervations of biceps femoris (BF), fibre type distribution, muscle architecture and the degree of anterior pelvic tilt, have all been implicated. Each of these variables impact upon HSI risk via a number of different mechanisms that include increasing hamstring muscle strain and altering the susceptibility of the hamstrings to muscle damage. Reported risk factors for HSIs include age, previous injury, ethnicity, strength imbalances, flexibility and fatigue. Of these, little is known, definitively, about why previous injury increases the risk of future HSIs. Nevertheless, interventions put in place to reduce the incidence of HSIs by addressing modifiable risk factors have focused primarily on increasing eccentric strength, correcting strength imbalances and improving flexibility. The response to these intervention programmes has been mixed with varied levels of success reported. A conceptual framework is presented suggesting that neuromuscular inhibition following HSIs may impede the rehabilitation process and subsequently lead to maladaptation of hamstring muscle structure and function, including preferentially eccentric weakness, atrophy of the previously injured muscles and alterations in the angle of peak knee flexor torque. This remains an area for future research and practitioners need to remain aware of the multifactoral nature of HSIs if injury rates are to decline.

A suspicious behaviour detection using a context space model for smart surveillance systems

Video surveillance systems using Closed Circuit Television (CCTV) cameras, is one of the fastest growing areas in the field of security technologies. However, the existing video surveillance systems are still not at a stage where they can be used for crime prevention. The systems rely heavily on human observers and are therefore limited by factors such as fatigue and monitoring capabilities over long periods of time. This work attempts to address these problems by proposing an automatic suspicious behaviour detection which utilises contextual information. The utilisation of contextual information is done via three main components: a context space model, a data stream clustering algorithm, and an inference algorithm. The utilisation of contextual information is still limited in the domain of suspicious behaviour detection. Furthermore, it is nearly impossible to correctly understand human behaviour without considering the context where it is observed. This work presents experiments using video feeds taken from CAVIAR dataset and a camera mounted on one of the buildings Z-Block) at the Queensland University of Technology, Australia. From these experiments, it is shown that by exploiting contextual information, the proposed system is able to make more accurate detections, especially of those behaviours which are only suspicious in some contexts while being normal in the others. Moreover, this information gives critical feedback to the system designers to refine the system.

Raman spectroscopy of the multi-anion mineral schlossmacherite (H3O,Ca)Al3(AsO4,PO4,SO4)2(OH)6

The mineral schlossmacherite (H3O,Ca)Al3(AsO4,PO4,SO4)2(OH)6 , a multi-cation-multi-anion mineral of the beudantite mineral subgroup has been characterised by Raman spectroscopy. The mineral and related minerals functions as a heavy metal collector and is often amorphous or poorly crystalline, such that XRD identification is difficult. The Raman spectra are dominated by an intense band at 864 cm-1, assigned to the symmetric stretching mode of the AsO43- anion. Raman bands at 809 and 819 cm-1 are assigned to the antisymmetric stretching mode of AsO43- . The sulphate anion is characterised by bands at 1000 cm-1 (ν1), and at 1031, 1082 and 1139 cm-1 (ν3). Two sets of bands in the OH stretching region are observed: firstly between 2800 and 3000 cm-1 with bands observed at 2850, 2868, 2918 cm-1 and secondly between 3300 and 3600 with bands observed at 3363, 3382, 3410, 3449 and 3537 cm-1. These bands enabled the calculation of hydrogen bond distances and show a wide range of H-bond distances.

Pollutant concentrations within households in Lao PDR and association with housing characteristics and occupants' activities

The paper presents the results of a study conducted to investigate indoor air quality within residential dwellings in Lao PDR. Results from PM 10, CO, and NO2 measurements inside 167 dwellings in Lao PDR over a five month period (December 2005-April 2006) are discussed as a function of household characteristics and occupant activities. Extremely high PM10 and NO2 concentrations (12 h mean PM10 concentrations 1275 ± 98 μg m-3 and 1183 ± 99 μg m-3 in Vientiane and Bolikhamxay provinces, respectively; 12 h mean NO2 concentrations 1210 ± 94 μg m-3 and 561 ± 45 μg m-3 in Vientiane and Bolikhamxay, respectively) were measured within the dwellings. Correlations, ANOVA analysis (univariate and multivariate), and linear regression results suggest a substantial contribution from cookingandsmoking.The PM10 concentrations were significantly higher in houses without a chimney compared to houses in which cooking occurred on a stove with a chimney. However, no significant differences in pollutantconcentrations were observed as a function of cooking location. Furthermore, PM10 and NO2 concentrations were higher in houses in which smoking occurred, suggestive of a relationship between increased indoor concentrations and smoking (0.05 < p < 0.10). Resuspension of dust from soil floors was another significant source of PM10 inside the house (634 μg m-3, p < 0.05).

The effects of verbal instruction on affective and expectancy learning

The current research assessed the effects of verbal instruction on affective and expectancy learning during repeated contingency reversals (Experiment 1 and during extinction (Experiment 2) in a picture–picture paradigm. Affective and expectancy learning displayed contingency reversal and extinction, but changes were slower for affective learning. Instructions facilitated reversal and extinction of expectancy learning but did not impact on affective learning. These findings suggest a differential susceptibility of affective and expectancy learning to verbal instruction and question previous reports that verbal instructions can accelerate the extinction of non-prepared fear learning in humans.

Exploring ethical dilemmas for principals arising from role conflict with school counsellors

Acting in the best interests of students is central to the moral and ethical work of schools. Yet tensions can arise between principals and school counsellors as they work from at times opposing professional paradigms. In this article we report on principals’ and counsellors’ responses to scenarios covering confidentiality and the law, student/teacher relationships, student welfare and psychological testing of students. This discussion takes place against an examination of ethics, ethical dilemmas and professional codes of ethics. While there were a number of commonalities among principals and school counsellors that arose from their common belief in education as a moral venture, there were also some key differences among them. These differences centred on the principals’ focus on the school as a whole and counsellors’ focus on the welfare of the individual student. A series of recommendations is offered to assist principals to navigate ethical dilemmas such as those considered in this article.

Doing blog research

Blogs and other online platforms for personal writing such as LiveJournal have been of interest to researchers across the social sciences and humanities for a decade now. Although growth in the uptake of blogging has stalled somewhat since the heyday of blogs in the early 2000s, blogging continues to be a major genre of Internet-based communication. Indeed, at the same time that mass participation has moved on to Facebook, Twitter, and other more recent communication phenomena, what has been left behind by the wave of mass adoption is a slightly smaller but all the more solidly established blogosphere of engaged and committed participants. Blogs are now an accepted part of institutional, group, and personal communications strategies (Bruns and Jacobs, 2006); in style and substance, they are situated between the more static information provided by conventional Websites and Webpages and the continuous newsfeeds provided through Facebook and Twitter updates. Blogs provide a vehicle for authors (and their commenters) to think through given topics in the space of a few hundred to a few thousand words – expanding, perhaps, on shorter tweets, and possibly leading to the publication of more fully formed texts elsewhere. Additionally, they are also a very flexible medium: they readily provide the functionality to include images, audio, video, and other additional materials – as well as the fundamental tool of blogging, the hyperlink itself. Indeed, the role of the link in blogs and blog posts should not be underestimated. Whatever the genre and topic that individual bloggers engage in, for the most part blogging is used to provide timely updates and commentary – and it is typical for such material to link both to relevant posts made by other bloggers, and to previous posts by the present author, both to background material which provides readers with further information about the blogger’s current topic, and to news stories and articles which the blogger found interesting or worthy of critique. Especially where bloggers are part of a larger community of authors sharing similar interests or views (and such communities are often indicated by the presence of yet another type of link – in blogrolls, often in a sidebar on the blog site, which list the blogger’s friends or favourites), then, the reciprocal writing and linking of posts often constitutes an asynchronous, distributed conversation that unfolds over the course of days, weeks, and months. Research into blogs is interesting for a variety of reasons, therefore. For one, a qualitative analysis of one or several blogs can reveal the cognitive and communicative processes through which individual bloggers define their online identity, position themselves in relation to fellow bloggers, frame particular themes, topics and stories, and engage with one another’s points of view. It may also shed light on how such processes may differ across different communities of interest, perhaps in correlation with the different societal framing and valorisation of specific areas of interest, with the socioeconomic backgrounds of individual bloggers, or with other external or internal factors. Such qualitative research now looks back on a decade-long history (for key collections, see Gurak, et al., 2004; Bruns and Jacobs, 2006; also see Walker Rettberg, 2008) and has recently shifted also to specifically investigate how blogging practices differ across different cultures (Russell and Echchaibi, 2009). Other studies have also investigated the practices and motivations of bloggers in specific countries from a sociological perspective, through large-scale surveys (e.g. Schmidt, 2009). Blogs have also been directly employed within both K-12 and higher education, across many disciplines, as tools for reflexive learning and discussion (Burgess, 2006).

Porous scaffold architecture guides tissue formation

Critical-sized bone defect regeneration is a remaining clinical concern. Numerous scaffold-based strategies are currently being investigated to enable in vivo bone defect healing. However, a deeper understanding of how a scaffold influences the tissue formation process and how this compares to endogenous bone formation or to regular fracture healing is missing. It is hypothesized that the porous scaffold architecture can serve as a guiding substrate to enable the formation of a structured fibrous network as a prerequirement for later bone formation. An ovine, tibial, 30-mm critical-sized defect is used as a model system to better understand the effect of the scaffold architecture on cell organization, fibrous tissue, and mineralized tissue formation mechanisms in vivo. Tissue regeneration patterns within two geometrically distinct macroscopic regions of a specific scaffold design, the scaffold wall and the endosteal cavity, are compared with tissue formation in an empty defect (negative control) and with cortical bone (positive control). Histology, backscattered electron imaging, scanning small-angle X-ray scattering, and nanoindentation are used to assess the morphology of fibrous and mineralized tissue, to measure the average mineral particle thickness and the degree of alignment, and to map the local elastic indentation modulus. The scaffold proves to function as a guiding substrate to the tissue formation process. It enables the arrangement of a structured fibrous tissue across the entire defect, which acts as a secondary supporting network for cells. Mineralization can then initiate along the fibrous network, resulting in bone ingrowth into a critical-sized defect, although not in complete bridging of the defect. The fibrous network morphology, which in turn is guided by the scaffold architecture, influences the microstructure of the newly formed bone. These results allow a deeper understanding of the mode of mineral tissue formation and the way this is influenced by the scaffold architecture. Copyright © 2012 American Society for Bone and Mineral Research.

Towards determining soft tissue properties for modelling spine surgery : current progress and challenges

Current complication rates for adolescent scoliosis surgery necessitate the development of better surgical planning tools to improve outcomes. Here we present our approach to developing finite element models of the thoracolumbar spine for deformity surgery simulation, with patient-specific model anatomy based on low-dose pre-operative computed tomography scans. In a first step towards defining patient-specific tissue properties, an initial 'benchmark' set of properties were used to simulate a clinically performed pre-operative spinal flexibility assessment, the fulcrum bending radiograph. Clinical data for ten patients were compared with the simulated results for this assessment and in cases where these data differed by more than 10%, soft tissue properties for the costo-vertebral joint (CVJt) were altered to achieve better agreement. Results from these analyses showed that changing the CVJt stiffness resulted in acceptable agreement between clinical and simulated flexibility in two of the six cases. In light of these results and those of our previous studies in this area, it is suggested that spinal flexibility in the fulcrum bending test is not governed by any single soft tissue structure acting in isolation. More detailed biomechanical characterisation of the fulcrum bending test is required to provide better data for determination of patient-specific soft tissue properties.

Risk of metabolic syndrome among children living in metropolitan Kuala Lumpur: A case control study

Background With the increasing prevalence of childhood obesity, the metabolic syndrome has been studied among children in many countries but not in Malaysia. Hence, this study aimed to compare metabolic risk factors between overweight/obese and normal weight children and to determine the influence of gender and ethnicity on the metabolic syndrome among school children aged 9-12 years in Kuala Lumpur and its metropolitan suburbs. Methods A case control study was conducted among 402 children, comprising 193 normal-weight and 209 overweight/obese. Weight, height, waist circumference (WC) and body composition were measured, and WHO (2007) growth reference was used to categorise children into the two weight groups. Blood pressure (BP) was taken, and blood was drawn after an overnight fast to determine fasting blood glucose (FBG) and full lipid profile, including triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). International Diabetes Federation (2007) criteria for children were used to identify metabolic syndrome. Results Participants comprised 60.9% (n = 245) Malay, 30.9% (n = 124) Chinese and 8.2% (n = 33) Indian. Overweight/obese children showed significantly poorer biochemical profile, higher body fat percentage and anthropometric characteristics compared to the normal-weight group. Among the metabolic risk factors, WC ≥90th percentile was found to have the highest odds (OR = 189.0; 95%CI 70.8, 504.8), followed by HDL-C≤1.03 mmol/L (OR = 5.0; 95%CI 2.4, 11.1) and high BP (OR = 4.2; 95%CI 1.3, 18.7). Metabolic syndrome was found in 5.3% of the overweight/obese children but none of the normal-weight children (p < 0.01). Overweight/obese children had higher odds (OR = 16.3; 95%CI 2.2, 461.1) of developing the metabolic syndrome compared to normal-weight children. Binary logistic regression showed no significant association between age, gender and family history of communicable diseases with the metabolic syndrome. However, for ethnicity, Indians were found to have higher odds (OR = 5.5; 95%CI 1.5, 20.5) compared to Malays, with Chinese children (OR = 0.3; 95%CI 0.0, 2.7) having the lowest odds. Conclusions We conclude that being overweight or obese poses a greater risk of developing the metabolic syndrome among children. Indian ethnicity is at higher risk compared to their counterparts of the same age. Hence, primary intervention strategies are required to prevent this problem from escalating.

Management characteristics and the decision to internationalize : exploration of exporters vs. non-exporters within the Chilean wine industry

The objective of this study was to identify key factors differentiating between exporters and non-exporters in the Chilean wine industry. Based on survey data collected from 61 wineries, the findings show that the main barriers for non-exporters are the lack of financial resources, limited quantities of stock for market expansion, management’s lack of knowledge and experience, and the high cost of travelling and participating in trade shows. The results also show that managers have educational levels and international experience exceeding those of other comparable New World wineries. Finally, in developing their main international markets, Chilean wineries did not target psychically close markets as identified in previous wine industry studies

Developing relationships that support learning and participation

Developing supportive, authentic and collaborative partnerships between all partners is crucial to inclusive school culture. This chapter highlights understandings of collaboration within such a culture. It also draws attention to what is involved in achieving these relationships, and identifies associated characteristics. In addition, it describes how successful collegial teams can be developed and ways in which teachers can work as collaborative members of these teams for students with disabilities within inclusive educational settings.

Challenging the female underperformance hypothesis

In their recent review of prior studies examining firm performance, Klapper and Parker (2010, p.7) conclude that “women entrepreneurs tend to underperform relative to their male counterparts.” However, Robb and Watson (2011) argue that much of this prior research is based on inappropriate performance measures and/or does not adequately control (due to data limitations) for important demographic differences. Given the conflicting findings reported in the literature, the aim of this study is to replicate the study by Robb and Watson (2011) to see if their findings can be generalized to another geographical location. Our results, based on an analysis of 209 female-owned and 263 male-owned young Australian firms, confirm those of Robb and Watson (2011). We believe that this outcome should help dispel the female underperformance myth; which if left unchallenged could result in inappropriate policy decisions and, more importantly, could discourage women from establishing new ventures.