Factors linked to participant attrition in a longitudinal occupational health surveillance program.

BACKGROUND: For occupational medical screening programs focused on long-term health surveillance, participant attrition is a significant barrier to success. We investigate demographic, medical history, and clinical data from National Supplemental Screening Program (NSSP) examinees for association with likelihood of return for a second exam (rescreening). METHODS: A total of 15,733 individuals completed at least one NSSP exam before December 31, 2016; of those, 4832 also completed a second exam on or before December 31, 2019. Stepwise logistic regression models were used to identify variables associated with whether a participant was rescreened in the NSSP. RESULTS: Individuals were less likely to return for rescreening if they had a history of any cancer; cardiovascular problems; diabetes or kidney disease; or if they used insulin. Age at time of first exam and job site category significantly influenced likelihood of return. Workers categorized as "guests" were more likely to return. Participants were less likely to return if they had an abnormal urinalysis, abnormal pulmonary function, pneumoconiosis, aortic atherosclerosis, or hearing loss at their initial exam. Participants who received a chest X-ray at their initial screening were more likely to return. CONCLUSIONS: The presence of health problems is strongly linked to screening program attrition. Participants who are older at the time of their initial screening exam are less likely to return. The discovery of several strong demographic, medical, and job associations reveals the importance for medical screening programs to understand and address factors that influence participant retention and, consequently, the effectiveness of long-term health surveillance activities.

Stabilization of self-mode-locked quantum dash lasers by symmetric dual-loop optical feedback.

We report experimental studies of the influence of symmetric dual-loop optical feedback on the RF linewidth and timing jitter of self-mode-locked two-section quantum dash lasers emitting at 1550 nm. Various feedback schemes were investigated and optimum levels determined for narrowest RF linewidth and low timing jitter, for single-loop and symmetric dual-loop feedback. Two symmetric dual-loop configurations, with balanced and unbalanced feedback ratios, were studied. We demonstrate that unbalanced symmetric dual loop feedback, with the inner cavity resonant and fine delay tuning of the outer loop, gives the narrowest RF linewidth and reduced timing jitter over a wide range of delay, unlike single and balanced symmetric dual-loop configurations. This configuration with feedback lengths of 80 and 140 m narrows the RF linewidth by ∼ 4-67x and ∼ 10-100x, respectively, across the widest delay range, compared to free-running. For symmetric dual-loop feedback, the influence of different power split ratios through the feedback loops was determined. Our results show that symmetric dual-loop feedback is markedly more effective than single-loop feedback in reducing RF linewidth and timing jitter, and is much less sensitive to delay phase, making this technique ideal for applications where robustness and alignment tolerance are essential.

Stabilization of self-mode-locked QDash lasers subject to simultaneous continuous-wave optical injection and optical feedback.

In this paper, we report stabilization of self-mode-locked two-section quantum-dash lasers on the widest range of delay using simultaneous optical injection and optical feedback. With continuous-wave optical injection, various wavelengths spanning a range from 1568 to 1578 nm were investigated and optimum wavelengths (1571.210 to 1572.710) yielding the narrowest RF linewidth and reduced timing jitter of slave laser were identified. In addition, the dependence of RF linewidth and pulse repetition rate on injected wavelength was further explored. Our results indicate that simultaneous optical feedback and optical injection significantly improves the RF linewidth across the widest delay range compared to optical feedback alone. Under fully resonant feedback and optimum injection parameters, a minimum RF linewidth of 1 kHz (instrument limited) was achieved with simultaneous optical injection plus optical feedback, which was >2× lower than optical feedback alone and more than 100× lower than free-running. This stabilization technique is implemented in an all-optical arrangement without optical/electrical conversion, which is ideal for high-repetition-rate devices and photonic integration.

Optimum stabilization of self-mode-locked quantum dash lasers using dual optical feedback with improved tolerance against phase delay mismatch.

We experimentally investigate the RF linewidth and timing jitter over a wide range of delay tuning in a self-mode-locked two-section quantum dash lasers emitting at ~ 1.55µm and operating at ~ 21 GHz repetition rate subject to single and dual optical feedback into gain section. Various feedback conditions are investigated and optimum levels determined for narrowest linewidth and reduced timing jitter for both single and dual loop configurations. We demonstrate that dual loop feedback, with the shorter feedback cavity tuned to be fully resonant, followed by fine tuning of the phase of the longer feedback cavity, gives stable narrow RF spectra across the widest delay range, unlike single loop feedback. In addition, for dual loop configurations, under fully resonant conditions, integrated timing jitter is reduced from 3.9 ps to 295 fs [10 kHz-100 MHz], the RF linewidth narrows from 100 kHz to < 1 kHz, with more than 30 dB fundamental side-mode suppression. We show that dual loop optical feedback with separate fine tuning of both external cavities is far superior to single loop feedback, with increased system tolerance against phase delay mismatch, making it a robust and cost-effective technique for developing practical, reliable and low-noise mode-locked lasers, optoelectronic oscillators and pulsed photonic circuits.

Asymmetric dual-loop feedback to suppress spurious tones and reduce timing jitter in self-mode-locked quantum-dash lasers emitting at 1.55 µm.

We demonstrate an asymmetric dual-loop feedback method to suppress external cavity side-modes induced in self-mode-locked quantum-dash lasers with conventional single- and dual-loop feedback. In this Letter, we report optimal suppression of spurious tones by optimizing the delay in the second loop. We observed that asymmetric dual-loop feedback, with large (∼8×) disparity in loop lengths, gives significant suppression in external-cavity side-modes and produces flat radio frequency (RF) spectra close to the main peak with a low timing jitter, compared to single-loop feedback. Significant reduction in RF linewidth and timing jitter was produced by optimizing the delay time in the second feedback loop. Experimental results based on this feedback configuration validate predictions of recently published numerical simulations. This asymmetric dual-loop feedback scheme provides simple, efficient, and cost-effective stabilization of optoelectronic oscillators based on mode-locked lasers.

Integrated approach to health screening of former department of energy workers detects both occupational and non-occupational illness.

BACKGROUND: The National Supplemental Screening Program (NSSP) uses a Total Worker Health(TM) approach to address U.S. Department of Energy (DOE) former worker health. This article provides the design of the integrated occupational health screening and promotion program. METHODS: The NSSP implemented a web-based relational health records system to process demographic, exposure, and clinical data. We present medical findings for 12,000 DOE former workers that completed an initial NSSP medical screening between October 1, 2005 and October 4, 2013. We discuss the DOE former worker participant population and the exposure-based and non-occupational medical screening tests used. RESULTS: The NSSP identified potential occupationally related health conditions in 40.5% of those screened. Notably, we identified 85.8% of participants with addressable non-occupational health conditions, many of which were previously undiagnosed. CONCLUSION: The NSSP demonstrates that the identification of potential occupational health issues in conjunction with addressable non-occupational health conditions provides former workers with information to more effectively manage health.

ePortfolios: Enhancing confidence in student radiographers' communication of radiographic anatomy and pathology. A cross-sectional study.

INTRODUCTION: In 2020, the Medical Radiation Practice Board of Australia made several revisions to its professional capabilities. To address this, medical radiation practitioners, including diagnostic radiographers, are required to escalate urgent findings in all radiographic settings. However, the confidence of radiographers in articulating descriptions of radiographic findings varies despite this requirement. This cross-sectional study explores how the implementation of eportfolio affects student self-perceived confidence in identifying and describing radiographic findings in both an academic and a clinical setting. METHODS: A Qualtrics survey was distributed to second-year radiography students who had used eportfolios. The survey comprised of four questions using a Likert-scale and one open-ended question. Quantitative data were analysed using the Wilcoxon signed-rank test and qualitative data was thematically assessed. RESULTS: Overall, 55 of 65 radiographic students (85%) completed the survey. Confidence (strongly agree and agree) decreased from 89% to 74% between academic and clinical environments when identifying abnormalities, and 89% to 73% when describing findings. This finding highlights the challenges students face when in the clinical environment. Wilcoxon signed rank test analysed a statistically significant relation between the two environments (P < 0.05). However, the relationship between identifying and describing skills was not statistically significant (P > 0.05). Following a review of the qualitative data, three recurring themes were identified among responses. CONCLUSION: ePortfolios assist in improving confidence in identification and description of radiographic abnormalities, particularly in an academic setting. The clinical environment presents unique challenges which may limit student clinical performance; however, this requires further investigation.

Interprofessional collaboration between medical imaging academics and linguists in developing communication skills.

INTRODUCTION/BACKGROUND: Effective communication is critical in all healthcare professions, including medical imaging. This is demonstrated across the professional capability requirements outlined by regulatory bodies that represent medical radiation practitioners around the world. Thus, it is imperative that university curricula provide students with opportunities to develop their communication skills to ensure graduates are prepared to deliver high-quality person-centred care (PCC). The aim of this educational perspective paper is to discuss an interprofessional collaboration between academics from medical imaging and a linguist from the Faculty of Medicine, Nursing and Health Sciences' health communication unit to develop and deliver a pre-clinical communication skills program for undergraduate medical imaging students at Monash University. This innovative program aims to address the unique communication challenges encountered during medical imaging examinations. DISCUSSION: Medical imaging programs tend to use a combination of lectures, role-play and structured workshops to teach communication skills to undergraduate students. These are normally run by medical imaging academics who have significant clinical experience as well as tacit intuitive understanding of communication challenges. This intuitive knowledge can be challenging to articulate to novice learners. In comparison, a linguist is an expert in the use and form of language in context, and can collaborate with medical imaging academics to support students in developing their understanding of communication as a tool for use in caring and compassionate practice as part of a PCC approach. This paper highlights an interprofessional collaboration between medical imaging academics and a linguist to develop and deliver an integrated communication skills program at Monash University, bringing together the expertise of both fields to support medical imaging students in effectively communicating with patients in the clinical context. CONCLUSION: The interprofessional collaboration between medical imaging academics and a linguist at Monash University shows early promise. Our collaborative pre-clinical communication skills curriculum development and delivery pioneers an innovative method within the medical imaging curriculum which integrates best practice from both medical imaging and linguistic fields.

Australian sonographers' perceptions of patient safety in ultrasound imaging: Part two - translation into practice.

Introduction: A lack of patient safety research hampers capacity to improve safety in healthcare.Ultrasound is often considered 'safe' as it does not use ionising radiation, a simplistic view of patient safety. Understanding sonographers' actions towards patient safety is crucial; however, self-reported measures cannot always predict behaviour. This study is part of a PhD exploring patient safety in medical diagnostic ultrasound. The aim of this paper is to explore sonographers' responses to the patient safety concerns identified in Part one of this study. The ultimate aim of the study is to inform the final phase of the doctoral study which will consider the next steps in improving the quality and safety of healthcare experienced by patients. Methods: A qualitative study using semi-structured, one-on-one interviews. The Theory of Planned Behaviour (TPB) explained how sonographers respond to perceived patient safety risks in practice. Results: Thirty-one sonographers were interviewed. Based on the seven themes identified in Part one of the study, results showed that incongruences exist between identifying patient safety risks and the actions taken in practice to manage these risks. Conclusion: The TPB showed that behavioural, normative and control beliefs impact sonographers' responses to perceived patient safety risks in practice and can lead to risk avoidance. Lack of regulation in ultrasound creates a challenge in dealing with Fitness to Practice issues. Collective actions are required to support sonographers in taking appropriate actions to enhance patient safety from multiple stakeholders including accreditation bodies, regulatory authorities, educational institutions and employers.

Australian sonographers' perceptions of patient safety in ultrasound imaging: Part 1 - identifying the main safety concerns, a qualitative study.

Introduction: Patient safety has been an undervalued component of quality healthcare but is a challenging area of research.Ultrasound is the most common imaging modality in the world. Research on patient safety in ultrasound is generally focused on bioeffects and safe operation of ultrasound equipment. However, other safety issues exist in practice that warrant consideration.This paper forms the first part of a PhD study exploring patient safety in medical diagnostic ultrasound, beyond the notion of bioeffects.The ultimate aim of the study is to inform the final phase of the research study which will consider the next steps in improving the quality and safety of healthcare experienced by patients. Methods: A qualitative study using semi-structured, one-on-one interviews. A thematic analysis categorised data into codes and generated final themes. Results: A heterogeneous mix of 31 sonographers, who reflected the profile of the profession in Australia, were interviewed between September 2019 and January 2020. Seven themes emerged from the analysis. These were bioeffects, physical safety, workload, reporting, professionalism, intimate examinations and infection control. Conclusion: This study presents a comprehensive analysis of sonographers' perceptions of patient safety in ultrasound imaging, not previously available in the literature. Consistent with the literature, patient safety in ultrasound tends to be viewed in technical terms through the potential for bioeffects of tissue damage or physical harm to the patient. However, other patient safety issues have emerged, and while not as well recognised, have the potential to negatively impact on patient safety.

Positive and negative effects of widespread badger culling on tuberculosis in cattle.

Human and livestock diseases can be difficult to control where infection persists in wildlife populations. For three decades, European badgers (Meles meles) have been culled by the British government in a series of attempts to limit the spread of Mycobacterium bovis, the causative agent of bovine tuberculosis (TB), to cattle. Despite these efforts, the incidence of TB in cattle has risen consistently, re-emerging as a primary concern for Britain's cattle industry. Recently, badger culling has attracted controversy because experimental studies have reached contrasting conclusions (albeit using different protocols), with culled areas showing either markedly reduced or increased incidence of TB in cattle. This has confused attempts to develop a science-based management policy. Here we use data from a large-scale, randomized field experiment to help resolve these apparent differences. We show that, as carried out in this experiment, culling reduces cattle TB incidence in the areas that are culled, but increases incidence in adjoining areas. These findings are biologically consistent with previous studies but will present challenges for policy development.

Interdisciplinary interprofessional education using an online learning environment called values exchange: A qualitative investigation.

INTRODUCTION: Interprofessional education (IPE) is implemented throughout the curricula of student healthcare professions as it is understood to provide positive impact on patient outcomes in the clinical environment. There are different methods to provide IPE such as through online learning or traditional face-to-face methods. However, there is a lack of research surrounding the use of Online Learning Environments (OLEs) to teach IPE. METHODS: In a pilot study, seventy-one undergraduate radiography students and twenty Master of Pharmacy students engaged in an ethical scenario using the OLE, Values Exchange (Vx). Following the activity, students were invited to complete an open-ended response question. Fourteen students responded and these data were used for qualitative analysis. RESULTS: A thematic analysis of the students' open-ended responses found the emergence of three major themes, namely; understanding the roles of other healthcare professionals, developing self-reflection skills and, preparing for the clinical environment. Students suggested that additional time allocated for undertaking the study would benefit their engagement in the activity. Students would benefit from added engagement in the Vx task in both the short and long term for IPE. CONCLUSION: Students are receptive in utilising contemporary approaches such as OLEs in furthering their IPE. Positive interpretations and suggestions by both radiography and pharmacy students in this study demonstrate how Vx as an OLE teaching tool can be used effectively. OLEs can overcome barriers that exist in face-to-face education experiences. OLEs should be considered for greater use within academic curricula of healthcare professions, but only if they have been evaluated for effectiveness.

Ameliorating the stability of erbium-doped fiber laser using saturable absorber fabricated by the pulsed laser deposition technique.

In this paper, we present the performance and stability of an erbium-doped fiber laser (EDFL) based on ZnO saturable-absorber (SA) prepared using two schemes: solution method (SM) and pulsed laser deposition technique (PLDT). It was observed that EDFL with ZnO-SA prepared using SM emits at 1561.25 nm under a pump power of 230 mW. As the pump power is increased from 22.2 mW to 75.3 mW, the pulse duration decreases from 24.91 to 10.69 µs, and the pulse repetition rates increase from 11.59 to 40.91 kHz. Besides at pump power of 75.3 mW, the peak power, pulse energy, and average output power are measured as 0.327 mW, 2.86 nJ, and 0.18 mW, respectively. However, when PLDT-based SA was incorporated into the ring cavity, the emission wavelength is noticed at 1568.21 nm at a pump power of 230 mW. With the increase in pump power from 22.2 mW to 418 mW, the pulse repetition rates increase from 10.79 to 79.37 kHz and the pulse width decreases from 23.58 to 5.6 µs. Furthermore, the peak power, pulse energy, and average output power are observed to be 10.9 mW, 74 nJ, and 5.35 mW, respectively. The stability of EDFL based on SAs prepared using SM and PLDT has also been investigated. To the best of the author's knowledge, it is the first comparison of performance and long-term stability of EDFL based on two experimental techniques SM and PLDT-based SAs. These findings suggest that PLDT-based SAs provides optimum stability over a long period and enhanced the performance of fiber lasers compared to the SAs prepared using the conventional SM technique. This study paves the way for the development of ultra-stable SAs for their potential applications in pulsed laser sources and photonic devices.

Impact of localized badger culling on tuberculosis incidence in British cattle.

Pathogens that are transmitted between wildlife, livestock and humans present major challenges for the protection of human and animal health, the economic sustainability of agriculture, and the conservation of wildlife. Mycobacterium bovis, the aetiological agent of bovine tuberculosis (TB), is one such pathogen. The incidence of TB in cattle has increased substantially in parts of Great Britain in the past two decades, adversely affecting the livelihoods of cattle farmers and potentially increasing the risks of human exposure. The control of bovine TB in Great Britain is complicated by the involvement of wildlife, particularly badgers (Meles meles), which appear to sustain endemic infection and can transmit TB to cattle. Between 1975 and 1997 over 20,000 badgers were culled as part of British TB control policy, generating conflict between conservation and farming interest groups. Here we present results from a large-scale field trial that indicate that localized badger culling not only fails to control but also seems to increase TB incidence in cattle.

Experimental investigation of different regimes of mode-locking in a high repetition rate passively mode-locked semiconductor quantum-dot laser.

We report experimental investigations on a two-section 16-GHz repetition rate InAs/GaAs quantum dot passively mode-locked laser. Near the threshold current, pseudo-periodic Q-switching with complex dynamics is exhibited. Mode-locking operation regimes characterized by different repetition rates and timing jitter levels are encountered up to twice the threshold current. Evolution of the RF spectrum and optical spectrum with current is compared. The different mode-locked regimes are shown to be associated with different spectral and temporal shapes, ranging from 1.3 to 6 ps. This point is discussed by introducing the existence of two different supermodes. Repetition rate evolution and timing jitter increase is attributed to the coupling between the dominant and the secondary supermodes.

Social group size affects Mycobacterium bovis infection in European badgers (Meles meles).

1. In most social animals, the prevalence of directly transmitted pathogens increases in larger groups and at higher population densities. Such patterns are predicted by models of Mycobacterium bovis infection in European badgers (Meles meles). 2. We investigated the relationship between badger abundance and M. bovis prevalence, using data on 2696 adult badgers in 10 populations sampled at the start of the Randomized Badger Culling Trial. 3. M. bovis prevalence was consistently higher at low badger densities and in small social groups. M. bovis prevalence was also higher among badgers whose genetic profiles suggested that they had immigrated into their assigned social groups. 4. The association between high M. bovis prevalence and small badger group size appeared not to have been caused by previous small-scale culling in study areas, which had been suspended, on average, 5 years before the start of the current study. 5. The observed pattern of prevalence might occur through badgers in smaller groups interacting more frequently with members of neighbouring groups; detailed behavioural data are needed to test this hypothesis. Likewise, longitudinal data are needed to determine whether the size of infected groups might be suppressed by disease-related mortality. 6. Although M. bovis prevalence was lower at high population densities, the absolute number of infected badgers was higher. However, this does not necessarily mean that the risk of M. bovis transmission to cattle is highest at high badger densities, since transmission risk depends on badger behaviour as well as on badger density.

Bovine tuberculosis in cattle and badgers in localized culling areas.

Bovine tuberculosis (TB) is a zoonotic disease that can have serious consequences for cattle farming and, potentially, for public health. In Britain, failure to control bovine TB has been linked to persistent infection of European badger (Meles meles) populations. However, culling of badgers in the vicinity of recent TB outbreaks in cattle has failed to reduce the overall incidence of cattle TB. Using data from a large-scale study conducted in 1998-2005, we show that badgers collected on such localized culls had elevated prevalence of Mycobacterium bovis, the causative agent of bovine TB, suggesting that infections in cattle and badgers were indeed associated. Moreover, there was a high degree of similarity in the M. bovis strain types isolated from cattle and associated badgers. This similarity between strain types appeared to be unaffected by time lags between the detection of infection in cattle and culling of badgers, or by the presence of purchased cattle that might have acquired infection elsewhere. However, localized culling appeared to prompt an increase in the prevalence of M. bovis infection in badgers, probably by disrupting ranging and territorial behavior and hence increasing intraspecific transmission rates. This elevated prevalence among badgers could offset the benefits, for cattle, of reduced badger densities and may help to explain the failure of localized culling to reduce cattle TB incidence.

Clinical educators' attitudes towards the use of technology in the clinical teaching environment. A mixed methods study.

INTRODUCTION: In healthcare, there is ongoing flux in expectations for students and practitioners. Establishing integrated systems of monitoring and evidencing students' development is imperative. With current trends towards the use of technology in tertiary education, online learning environments (OLEs) could constitute more effective evidencing of student progress in the clinical environment. However, there is little research exploring clinical educators' experiences with implementing technology in clinical education. The research aimed to: Examine clinical educators' attitudes towards technology and its use in clinical education. Explore clinical educators' experiences of implementing technologies in a clinical environment. METHODS: A mixed methods approach was taken to explore the aims. A previously validated technology attitude survey (TAS) was used with slight modifications, as well as open-ended qualitative responses. These explored clinical educators' experiences of the implementation of one specific OLE (PebblePad™) in their clinical environments. The survey was sent to clinical educators involved in the supervision of Medical Imaging students on clinical placement. RESULTS: Clinical educators play pivotal roles in students' professional development and, given current trends in tertiary education, are under increasing pressure to utilise OLEs. This poses particular challenges in clinical environments. Irrespective of the challenges, successful implementation of technology in any environment is dependent on the attitudes of the users. CONCLUSIONS: Clinical environments have specific challenges when implementing technology such as access to computers and time constraints on practitioners. Even with positive attitudes towards technology, a change in pedagogical outlook when using technology in clinical teaching is necessary.