Carbonate-Metal Reactions in the Lower Mantle

Carbonates are important carbon-bearing phases in the mantle. While their role in upper mantle petrologic processes has been well studied, their effect on phase relations, melting, and transport properties in the lower mantle is less understood. The stability of carbonates in the mantle depends on a host of factors, including pressure, temperature, oxygen fugacity, and reactions with surrounding mantle phases. To understand the stability of carbonates in the presence of metal in the lower mantle, carbonate-metal reaction experiments on the Fe-Si-Ca-Mg-C-O system were conducted up to 124 GPa and 3200 K. We find that carbonates react with iron alloys to form silicates, iron carbides, and oxides. However, the temperature at which these reactions occur increases with pressure, indicating that along a geotherm in the lowermost mantle carbonates are the stable carbon-bearing phase. Carbon is found to be less siderophilic at high-pressure compared to silicon.

The Urgent Need for an Evidence-Based Digital Mental Health Practice Model of Care for Youth

Australian providers of mental health services and support for young people include private and public allied health providers, government initiatives (eg, headspace), nongovernment organizations (eg, Kids Helpline), general practitioners (GPs), and the hospital system. Over 20 years of research has established that many young people prefer to seek mental health support online; however, clear client pathways within and between online and offline mental health services are currently lacking. The authors propose a Digital Mental Health Practice model of care for youth to assist with digital mental health service mapping. The proposed model offers accessible pathways for a client to engage with digital mental health services, provides clear navigation to access support for individual needs, and facilitates a seamless connection with offline mental health services using a transferable electronic health records system. This future-looking model also includes emerging technologies, such as artificial intelligence and the metaverse, which must be accounted for as potential tools to be leveraged for digital therapies and support systems. The urgent need for a user-centered Digital Mental Health Practice model of care for youth in Australia is discussed, highlighting the shortcomings of traditional and existing online triage models evident during the COVID-19 pandemic, and the complex challenges that must be overcome, such as the integration of diverse mental health care providers and establishment of a robust electronic health records system. Potential benefits of such a model include reduced pressure on emergency rooms, improved identification of immediate needs, enhanced referral practices, and the establishment of a cost-efficient national digital mental health care model with global applicability. The authors conclude by stressing the consequences of inaction, warning that delays may lead to more complex challenges as new technologies emerge and exacerbate the long-term negative consequences of poor mental health management on the economic and biopsychosocial well-being of young Australians.

The Reel Health Care Professionals of Instagram: A Systematic Review

Social media and health research have covered the benefits for the public and patients as users. Specifically, this has focused on searching for health information, connecting with others experiencing similar health issues, and communicating with their health professionals. Recently, there has been a shift in research to focus on health care professionals as users as they participate in professional development, improve communication with patients, and contribute to health research and service. However, such research has predominantly focused on text-based platforms, namely Facebook and Twitter. The scope of this article is a systematic review of publications on health care professionals' use of the image-based platform Instagram, according to the preferred reporting items for systematic reviews and meta-analyses guidelines. This study, drawing from 51 articles, shows how health care professionals use Instagram, and reveals that these professionals utilize the platform to address health concerns that may not necessarily align with their specific expertise. Images were the common format of posts created by health care professionals, with six content types identified: (a) educational, (b) promotional, (c) patient experience, (d) personal, (e) emotion based, and (f) other. Three measures of post engagement were used by researchers, including (a) likes and comments, (b) use of hashtags, and (c) number of followers. This study also identified the dangers of misleading users, including (a) lack of credentials reported, (b) edited images, (c) quality of content, and (d) patient and client confidentiality issues. In conclusion, insights into the advantages of health care professionals' use of Instagram and ways in which they can maximize its use to reach and engage with their target audience are provided.

Health Professionals' Use of Online Communities for Interprofessional Peer Education

Online communities in health care are well established as technologies for facilitating interactions between patients with common conditions and communication between patients and health professionals. Less well known is how health professionals use these platforms to connect with their peers, particularly for interprofessional education or support. We present early results from our exploratory international mixed methods (survey and interview) study of health professionals' experience of engaging with online communities for interprofessional peer education. Our results show that health professionals had relatively high levels of confidence engaging with multiple platforms. They used the platforms to formally and informally share evidence-based content, engage in collegial debate and connect with international colleagues. Health professionals are keen to engage with online communities for education and are aware of how these sites' functionality can promote engagement with interdisciplinary peers.

Mental Health Help-Seeking Behavior of Male Video Game Players: An Online Survey

Video gaming is a popular pastime for young males, having been shown to have both positive and negative effects on players' mental health. The aim of the current study was to ascertain the rate that male video gamers may seek mental health support for mental ill-health generally. The secondary aims were to (a) identify the most prolific barriers to seeking help; (b) determine how confident this group is to seek help; and (c) whether the variance in help-seeking efficacy be explained, in part, by age, hours gamed, self-esteem, and social capital. The survey included sections on demographic information, standardized measures of self-esteem (The Rosenberg Self-Esteem Scale), social capital (The Social Capital in Gaming Scale), help-seeking efficacy (Self-Efficacy to Seek Mental Health Care Scale), and non-standardized measures of help-seeking behavior and help-seeking barriers. The survey of 2,515 participants had a mean age of 21.37 years. The analysis identified that most participants had not sought mental health support for themselves. The most prolific barriers for this cohort to seek help were cost, confidentiality, and trust. Confidence to seek help was rated the lowest for overcoming embarrassment, understanding information, and coping with others' reactions. Help-seeking efficacy was found to be significantly predicted by age, hours spent gaming, self-esteem, and social capital. Low rates of seeking help, coupled with identifying the significant barriers of this group to seek help, may inform researchers aiming to develop targeted interventions for male youth interested in gaming and who are exhibiting mental ill-health to gain initial access, or engage more often, with mental health services when needed. Further research is recommended for investigating male gamers' insights in determining how to overcome the identified barriers for this cohort to improve mental health seeking behavior rather than avoidant behavior. From this, stigma reduction and ease of access to digital mental health services could be improved.

Providing Self-Led Mental Health Support Through an Artificial Intelligence-Powered Chat Bot (Leora) to Meet the Demand of Mental Health Care

Digital mental health services are becoming increasingly valuable for addressing the global public health burden of mental ill-health. There is significant demand for scalable and effective web-based mental health services. Artificial intelligence (AI) has the potential to improve mental health through the deployment of chatbots. These chatbots can provide round-the-clock support and triage individuals who are reluctant to access traditional health care due to stigma. The aim of this viewpoint paper is to consider the feasibility of AI-powered platforms to support mental well-being. The Leora model is considered a model with the potential to provide mental health support. Leora is a conversational agent that uses AI to engage in conversations with users about their mental health and provide support for minimal-to-mild symptoms of anxiety and depression. The tool is designed to be accessible, personalized, and discreet, offering strategies for promoting well-being and acting as a web-based self-care coach. Across all AI-powered mental health services, there are several challenges in the ethical development and deployment of AI in mental health treatment, including trust and transparency, bias and health inequity, and the potential for negative consequences. To ensure the effective and ethical use of AI in mental health care, researchers must carefully consider these challenges and engage with key stakeholders to provide high-quality mental health support. Validation of the Leora platform through rigorous user testing will be the next step in ensuring the model is effective.

Increasing Access to Mental Health Services: Videogame Players' Perspectives

Young men's mental health is at the forefront of global public health concerns. Young males, who have a high incidence of mental health disorders, are a population that accesses services at lower rates than females and makes up the majority of videogame players. By considering the unique perspectives of digitally connected individuals on mental health service delivery, interventions may be designed to address their needs with a higher likelihood of success. This study investigated international male videogamers' perspectives on how their access to mental health services could be improved via an open-ended survey question. From a total of 2515 completed surveys, 761 responded to the qualitative question. Of these, the 71 responses that discussed access to and provision of mental healthcare services are reported in this article. Results suggest that digital mental health services were a promising way to reach this group. Anonymity and confidentiality were found to be important factors when considering online mental health services. Male videogame players identified a preference for both online and in-person services that are delivered synchronously, one-on-one with an expert practitioner, and readily available in settings that individuals find comfortable.

A quality improvement study: Optimizing pneumococcal vaccination rates in children with cochlear implants

Children with cochlear implants are at increased risk of invasive pneumococcal disease, with national and international guidelines recommending additional pneumococcal vaccines for these children. This study aimed to examine the pneumococcal immunization status and rate of invasive pneumococcal disease in children with cochlear implants at a tertiary paediatric hospital over a 12-year period. Additionally, the impacts of vaccination reminders and a dedicated immunization clinic on pneumococcal vaccination rates were assessed. This quality improvement study included 200 children who had received a cochlear implant through the Children's Hearing Implant Program at a tertiary paediatric hospital servicing the state of Western Australia. The majority of children (88%) were not up to date with additionally recommended pneumococcal vaccinations. Over the 12-year study period, 2% of children developed invasive pneumococcal disease associated with cochlear implant infections. Generic and personalized electronic immunization reminders improved pneumococcal vaccine up-take in this paediatric cochlear implant setting from 12% (19/153) at baseline to 49% (75/153, p < 0.0001) post implementation. The value of a nurse-led dedicated immunization clinic was also demonstrated with all children (42/42, 100%) up to date with Prevenar13 and the majority (34/42, 81%) up to date with Pneumovax23 post initiation of this referral pathway. These data support the expansion of this model to other medically-at-risk paediatric groups that have been highlighted consistently to be under-vaccinated.

Measurement of Lepton-Jet Correlation in Deep-Inelastic Scattering with the H1 Detector Using Machine Learning for Unfolding

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

A plant-infecting subviral RNA associated with poleroviruses produces a subgenomic RNA which resists exonuclease XRN1 in vitro

Subviral agents are nucleic acids which lack the features for classification as a virus. Tombusvirus-like associated RNAs (tlaRNAs) are subviral positive-sense, single-stranded RNAs that replicate autonomously, yet depend on a coinfecting virus for encapsidation and transmission. TlaRNAs produce abundant subgenomic RNA (sgRNA) upon infection. Here, we investigate how the well-studied tlaRNA, ST9, produces sgRNA and its function. We found ST9 is a noncoding RNA, due to its lack of protein coding capacity. We used resistance assays with eukaryotic Exoribonuclease-1 (XRN1) to investigate sgRNA production via incomplete degradation of genomic RNA. The ST9 3' untranslated region stalled XRN1 very near the 5' sgRNA end. Thus, the XRN family of enzymes drives sgRNA accumulation in ST9-infected tissue by incomplete degradation of ST9 RNA. This work suggests tlaRNAs are not just parasites of viruses with compatible capsids, but also mutually beneficial partners that influence host cell RNA biology.

The Use of Virtual Reality for Managing Psychological Distress in Adolescents: Systematic Review

Acute and chronic psychological distress are prevalent during adolescence and can have negative impacts on adolescents in all life domains. The aim of this systematic review was to appraise the use of virtual reality (VR) interventions to manage symptoms of psychological distress symptoms among adolescents. MEDLINE, PubMed, PsycINFO, and Scopus databases were searched up to June 2020. Available citations were de-duplicated and screened by two authors using title and abstract information. A total of 301 articles were retained for full-text evaluation next to eligibility criteria. Empirical studies of all designs and comparator groups were included if these appraised the impact of an immersive VR intervention on any standardized measure indicative of psychological distress in an adolescent sample. Data were extracted into a standardized coding sheet. Results were tabulated and discussed with a narrative synthesis due to the heterogeneity between studies. A total of seven studies met inclusion criteria. There were four randomized controlled trials and three uncontrolled pilot studies on new VR interventions. Distress-related issues included: state-anxiety, venepuncture, risk taking, public speaking anxiety, social anxiety disorder, sexual victimization, and chemotherapy administration. All studies reported significant changes on outcome measures after VR treatment. Six studies reported small-to-large reductions in symptoms. The average attrition rate was 3.6 percent during the active VR treatment phase. Treatment acceptability was high in the studies that assessed user engagement factors. The VR technology can provide a safe, rapidly efficacious, and acceptable treatment modality for managing psychological distress in several key adolescent populations.

Pollen Loads of Flower Visitors to Açaí Palm (Euterpe oleracea) and Implications for Management of Pollination Services

Understanding the functional roles of different pollinator species is crucial to the development of sustainable farming practices in pollinator-dependent crops. However, this can be challenging for crop plants in tropical regions with hyper-diverse pollinator communities. Here, we assess pollen loads of different insect visitors to inflorescences of açaí palm (Euterpe oleracea), the most important native crop in the Amazon estuary region. Flower-visiting insects were collected from pistillate (female) inflorescences at eight sites, including four managed floodplain forests and four plantations. Pollinator Importance Value Index (PIVI) and Relative Importance (RI) scores were calculated for common visitor taxa (≥ 10 individuals) using sum visit frequencies and median pollen loads. Pollen load analyses revealed that over seventy insect taxa, including bees, flies, beetles, wasps and ants, were effective vectors of E. oleracea pollen. Native bees, including both solitary and eusocial taxa, were the most efficient pollen vectors, with median pollen loads at least eight times higher than those of the next best insect group (flies). Insect pollen loads were at their highest between 0800 and 1300 hours, and four insect taxa had RI scores > 0.05, including two meliponine bees belonging to the Trigona genus (Trigona branneri Cockerell and Trigona pallens Fabricius) and two halictid bee genera (Augochloropsis and Dialictus). Our results suggest that native bees play an important role in açaí pollination and should be the primary focus of pollinator management in açaí production systems.

Adjunctive protein synthesis inhibitor antibiotics for toxin suppression in Staphylococcus aureus infections: a systematic appraisal

Protein synthesis inhibitor antibiotics inhibit synthesis of new proteins, including exotoxins and other important virulence determinants in Staphylococcus aureus. A summary of the literature regarding the use of adjunctive protein synthesis inhibitors for toxin suppression in the setting of S. aureus infections is presented.

Facebook as a recruitment tool for adolescent health research: a systematic review

BACKGROUND

Researchers are increasingly using social media to recruit participants to surveys and clinical studies. However, the evidence of the efficacy and validity of adolescent recruitment through Facebook is yet to be established.

OBJECTIVE

To conduct a systematic review of the literature on the use of Facebook to recruit adolescents for health research.

DATA SOURCES

Nine electronic databases and reference lists were searched for articles published between 2004 and 2013.

STUDY ELIGIBILITY CRITERIA

Studies were included in the review if: 1) participants were aged ≥ 10 to ≤ 18 years, 2) studies addressed a physical or mental health issue, 3) Facebook was identified as a recruitment tool, 4) recruitment details using Facebook were outlined in the methods section and considered in the discussion, or information was obtained by contacting the authors, 5) results revealed how many participants were recruited using Facebook, and 6) studies addressed how adolescent consent and/or parental consent was obtained.

STUDY APPRAISALS AND SYNTHESIS METHODS

Titles, abstracts, and keywords were scanned and duplicates removed by 2 reviewers. Full text was evaluated for inclusion criteria, and 2 reviewers independently extracted data.

RESULTS

The search resulted in 587 publications, of which 25 full-text papers were analyzed. Six studies met all the criteria for inclusion in the review. Three recruitment methods using Facebook was identified: 1) paid Facebook advertising, 2) use of the Facebook search tool, and 3) creation and use of a Facebook Page.

CONCLUSIONS

Eligible studies described the use of paid Facebook advertising and Facebook as a search tool as methods to successfully recruit adolescent participants. Online and verbal consent was obtained from participants recruited from Facebook.

Manual therapy, exercise therapy, or both, in addition to usual care, for osteoarthritis of the hip or knee. 2: economic evaluation alongside a randomized controlled trial

OBJECTIVE

To evaluate the cost effectiveness of manual physiotherapy, exercise physiotherapy, and a combination of these therapies for patients with osteoarthritis of the hip or knee.

METHODS

206 Adults who met the American College of Rheumatology criteria for hip or knee osteoarthritis were included in an economic evaluation from the perspectives of the New Zealand health system and society alongside a randomized controlled trial. Resource use was collected using the Osteoarthritis Costs and Consequences Questionnaire. Quality-adjusted life years (QALYs) were calculated using the Short Form 6D. Willingness-to-pay threshold values were based on one to three times New Zealand's gross domestic product (GDP) per capita of NZ$ 29,149 (in 2009).

RESULTS

All three treatment programmes resulted in incremental QALY gains relative to usual care. From the perspective of the New Zealand health system, exercise therapy was the only treatment to result in an incremental cost utility ratio under one time GDP per capita at NZ$ 26,400 (-$34,081 to $103,899). From the societal perspective manual therapy was cost saving relative to usual care for most scenarios studied. Exercise therapy resulted in incremental cost utility ratios regarded as cost effective but was not cost saving. For most scenarios combined therapy was not as cost effective as the two therapies alone.

CONCLUSIONS

In this study, exercise therapy and manual therapy were more cost effective than usual care at policy relevant values of willingness-to-pay from both the perspective of the health system and society. Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12608000130369.

E-health as a life long learning process: how to prepare health professionals for this journey

BACKGROUND

The e-health environment is a rapidly changing one. To effectively engage with technology for healthcare delivery, health professionals must be able to adapt to this constantly evolving environment very quickly. Learning and adapting to new e-health technologies is a life-long learning process.

OBJECTIVE

This study examined the effectiveness of incorporating self-directed and transformative learning approaches to introduce health sciences students to e-health concepts and skills.

METHODS

Two surveys were conducted to measure students' e-health knowledge and their perceived self-efficacy in using commonly available software to complete tasks required for an assessment in the unit of study. These surveys were conducted at the beginning and the end of the semester. Paired t-tests with Bonferroni adjustment were used to examine the effect of the teaching approach on students' self-perceived efficacy.

RESULTS

It was found that students showed significant improvement in their knowledge of, and perceived efficacy in using, commonly available software to carry out spreadsheet, database and data manipulation operations after intervention.

CONCLUSION

This study shows that the combined self-directed and transformative teaching and learning approach is effective in helping students to identify their learning needs and develop skills to seek out resources that enable them to learn new e-health skills and concepts in a self-directed manner.

The effect of e-health contents on health science students' attitude toward the efficiency of health ICT in care provision

OBJECTIVE

This study aimed to examine the effects of e-health education content on the attitude of undergraduate health science students towards the efficiency of health ICT in healthcare provision.

METHODS

A cross-sectional survey design was used. Participants were Health Sciences students attending The University of Sydney. Students were divided into three groups: junior students enrolled in a subject with non e-health content; senior students enrolled in a subject with non e-health content; and students enrolled in a subject with e-health content. Students' attitude towards the efficiency of ICT in healthcare provision was measured by a modified version of the Information Technology Attitude Scales for Health (ITASH).

RESULTS

Students enrolled in the subject with e-health content had a significantly higher average baseline attitude score than the other two groups (T198=-3.47, p=0.001; T93=-2.43, p=0.017). The repeat measures analysis yielded a result with significant interaction between survey time and student group (F2, 267=4.99, p=0.007) suggesting that changes of score was dependent on student group status.

CONCLUSION

Subjects rich in e-health content significantly enhanced student attitudes, even with a group of students with a rather positive initial attitude. To facilitate the uptake and utilisation of health ICT by the future health workforce, it is important for tertiary educational institutes to provide students with sufficient exposure to specific health-related ICT training, via specifically designed subjects delivering both generic and specific e-health content.

Age, cohort and period effects on hip fracture incidence: analysis and predictions from New Zealand data 1974-2007

Hip fractures are substantial problem worldwide. The increase in rate with age does not continue into very old age. Rates decline in successive birth cohorts. If the increasing trend in period effect continues, there will be a substantial increase in hip fracture incidence.

INTRODUCTION

The purpose of this study is to (1) determine incidence rates for fracture neck of femur (FNF) for the period 1974-2007, (2) estimate age, cohort, and period effects, and (3) predict the burden of FNF in 2025.

METHODS

Age adjusted incidence rates were estimated using New Zealand hospital discharge data for 1974-2007. Age-period-cohort modeling was used to estimate individual effects of these factors after adjusting for the other two factors. Future fracture burden was estimated under two scenarios.

RESULTS

Age-adjusted rates for women increased from 1974 to 1987 whereas rates for men have increased from 1974 until 2007. Risk increased from 70 years of age but dropped among the very elderly. Period effects showed a steady increase in risk throughout 1974-2007. In contrast, the risk was lower in later cohorts. If there is no change in the period effect from 2007 we estimate a reduction in the burden of illness from FNF, especially for women. However if the period effect continues to increase, there will be substantial increases in FNF incidence, especially for men.

CONCLUSIONS

The effect of population aging on FNF incidence is predictable because projections are based on an existing population. The increasing health and improvement in measures of physical status of older people through the last century, explain the decline in FNF incidence in later cohorts. The steady increase in period effect may be due to increased survival of the very frail. This burden of illness resulting from FNFs must be addressed by population based, research proven approaches to fall and fracture prevention.

A High-Pressure Test of Birch's Law

The compressional wave velocities of polycrystalline NaCl and KCl have been measured to over 17 gigapascals, with the use of Brillouin scattering and the diamond anvil cell. This pressure corresponds to 40% compression for NaCl and 60% compression for KCl (including the volume change across the B1-B2 transition). The data obey Birch's Law, which predicts that the velocity of each material is linear with density, except across the B1-B2 phase transition in KCl. This deviation from Birch's Law can be rationalized in terms of an interatomic potential model wherein the vibrational frequencies of the nearest neighbor bonds decrease when going to the eight-coordinated B2 structure from the six-coordinated B1 structure.

Catalytic cycles for the reduction of [UO2]2+ by cytochrome c7 proteins proposed from DFT calculations

The mechanism of the reduction of the hydrated uranyl cation, [UO2](2+), by the cytochromes G. sulfurreducens and D. acetoxidans has been studied using density functional theory calculations. We propose that the initial electron transfer step from the heme is to a cation-cation complex in the case of D. acetoxidans, but for G. sulfurreducens, it is to a single uranyl cation, which then forms a U(V)-U(VI) complex with a second uranyl cation. For both enzymes, the subsequent catalytic pathways are very similar. A U(V)-U(V) complex is formed, which then undergoes disproportionation via two successive protonation steps of one uranyl group, to give a U(VI)-U(IV) complex which dissociates to individual U(VI) and U(IV) species, the former being bound at the enzyme active site. Intermediate structures along the catalytic pathway are consistent with EXAFS data.

Continuous positive airway pressure in heart failure patients with obstructive sleep apnoea

BACKGROUND

The aim of the study was to study the effect of 6 months of continuous positive airway pressure (CPAP) in community heart failure (HF) patients with obstructive sleep apnoea (OSA).

METHODS

Clinically stable outpatients with HF and OSA (left ventricular ejection fraction (LVEF) <45%, apnoea/hypopnoea index >15/h, n = 19) treated with CPAP and a control group (LVEF <45%, apnoea/hypopnoea index <10/h, n = 7) were compared at baseline and at 6 months by Minnesota heart failure score, Epworth sleepiness score, shuttle walk distance, brain natriuretic peptide, urinary catecholamines and echocardiographic indices using paired t-test, McNemar's tests and effect sizes.

RESULTS

In HF patients with OSA, CPAP improved LVEF (35.9 +/- 6.1% to 40.6 +/- 8.0%, P = 0.015), decreased LV end-systolic volume (152 +/- 74 to 135 +/- 62 cm(3), P = 0.03), systolic blood pressure (P = 0.04) and sleepiness (Epworth sleepiness score 8.8 +/- 4.8 to 6.3 +/- 3.2, P = 0.01), whereas walk distance, catecholamines, brain natriuretic peptide levels and symptoms were unchanged. These outcomes did not change in the HF control group.

CONCLUSION

In community HF patients with OSA, CPAP therapy over 6 months improved LVEF, systolic blood pressure and sleepiness, but not sympathetic activation, brain natriuretic peptide or exercise levels. Acceptance was relatively low, potentially limiting therapeutic effectiveness.

Measurement of temperature distributions across laser heated samples by multispectral imaging radiometry

Two-dimensional temperature mapping of laser heated diamond anvil cell samples is performed by processing a set of four simultaneous images of the sample, each obtained at a narrow spectral range in the visible to near infrared. The images are correlated spatially, and each set of four points is fitted to the Planck radiation function to determine the temperature and the emissivity of the sample, using the gray body approximation. The method is tested by measuring the melting point of Pt at 1 bar and measuring laser heated Fe at 20 GPa in the diamond anvil cell. The accuracy and precision are shown to compare well to standard spectroradiometry, and the effect of imaging resolution on the measured distribution is evaluated. The principal advantages of the method are (1) the temperature and emissivity of the sample are mapped in two dimensions; (2) chromatic aberrations are practically eliminated by independent focusing of each spectral band; and (3) all of the spectral images are obtained simultaneously, allowing temporal variations to be studied. This method of measuring temperature distributions can be generalized to other hot objects besides laser heated spots.

Reducing hazard related falls in people 75 years and older with significant visual impairment: how did a successful program work?

BACKGROUND

In a randomized controlled trial testing a home safety program designed to prevent falls in older people with severe visual impairment, it was shown that the program, delivered by an experienced occupational therapist, significantly reduced the numbers of falls both at home and away from home.

OBJECTIVES

To investigate whether the success of the home safety assessment and modification intervention in reducing falls resulted directly from modification of home hazards or from behavioral modifications, or both.

METHODS

Participants were 391 community living women and men aged 75 years and older with visual acuity 6/24 meters or worse; 92% (361 of 391) completed one year of follow up. Main outcome measures were type and number of hazards and risky behavior identified in the home and garden of those receiving the home safety program, compliance with home safety recommendations reported at six months, location of all falls for all study participants during the trial, and environmental hazards associated with each fall.

RESULTS

The numbers of falls at home related to an environmental hazard and those with no hazard involved were both reduced by the home safety program (n = 100 participants) compared with the group receiving social visits (n = 96) (incidence rate ratios = 0.40 (95% confidence interval, 0.21 to 0.74) and 0.43 (0.21 to 0.90), respectively).

CONCLUSIONS

The overall reduction in falls by the home safety program must result from some mechanism in addition to the removal or modification of hazards or provision of new equipment.

An observational study of changes to long-term medication after admission to an intensive care unit

Many patients admitted to intensive care units consume long-term medication. New drugs may be commenced during intensive care intended for the short term or longer. Patients are often cared for by several teams during hospital admission and long-term medication may inadvertently be permanently discontinued. Following admission, new therapies relevant only in the short term could be continued beyond intensive care and hospital discharge. We conducted a retrospective analysis of drug prescription by examining patients' notes and charts before, during and after intensive care admission. Of 197 drugs prescribed up to intensive care admission to 59 patients, 112 (57%) were stopped. Ninety-nine of these were not reintroduced by intensive care discharge and 34 were not reintroduced by hospital discharge. Of 154 drugs commenced during intensive care, 96 (62%) had no listed reason for their introduction. Twenty-eight were continued beyond hospital discharge, some without apparent ongoing indication. Reliable mechanisms to prevent prescription errors are required.

Continuous positive airway pressure reduces daytime sleepiness in mild to moderate obstructive sleep apnoea: a meta-analysis

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) affects an estimated 2-4% of the middle aged population. Meta-analyses of randomised controlled trials have shown that the severe presentation of the syndrome (apnoea hypopnoea index (AHI) >30/hour) is effectively treated with continuous positive airway pressure (CPAP). Until recently there have been insufficient data to determine whether CPAP improves sleepiness in the larger subgroup with mild to moderate OSAS (AHI 5-30/hour).

METHODS

A systematic search of Medline and a hand search identified seven randomised controlled trials where CPAP was compared with either a placebo or with conservative management in the treatment of mild to moderate OSAS (AHI 5-30/hour). All trials used the Epworth Sleepiness Scale (ESS), four used the Multiple Sleep Latency Test (MSLT), and three used the Maintenance of Wakefulness Test (MWT) to measure sleepiness.

RESULTS

Meta-analyses indicated that CPAP significantly reduced subjective daytime sleepiness (ESS) by 1.2 points (95% CI 0.5 to 1.9, p = 0.001), improved objective daytime wakefulness (MWT) by 2.1 minutes (95% CI 0.5 to 3.7, p = 0.011), but did not affect objective daytime sleepiness (MSLT, mean benefit -0.2 minutes, 95% CI -1.0 to 0.6, p = 0.6). The two significant effects were small (effect size <0.30).

CONCLUSIONS

CPAP elicits small improvements in subjective sleepiness and objective wakefulness in people with mild to moderate OSAS. However, the effects on sleepiness are of limited clinical significance.

Internet Use by the Socially Fearful: Addiction or Therapy?

The Internet has often been argued to have adverse psychological consequences, such as depression or anxiety symptoms, among "over-users." The present study offers an alternative understanding, suggesting the Internet may be used as a forum for expanding social networks and consequently enhancing the chance of meaningful relationships, self-confidence, social abilities, and social support. An online sample of 188 people was recruited over the Internet, while paper and pencil tests were administered to an offline sample group of 27 undergraduate university students, who were regular Internet users. Subjects completed the Zung Depression Scale (ZDS), Depression, Anxiety and Stress Scales (DASS), Eysenck Personality Questionnaire?Revised Short Scale (EPQ-R Short), Fear of Negative Evaluation (FNE) scale, Internet Use Questionnaire (IUQ), and an Internet Effects Questionnaire (IEQ). Results suggested that there was no relationship between time spent online and depression, anxiety, or social fearfulness. Those who primarily used the Internet for online chat believed that the Internet is psychologically beneficial to them, but also believed that frequent Internet users are lonely and that the Internet can be addictive. It is argued that "chat" users who are socially fearful may be using the Internet as a form of low-risk social approach and an opportunity to rehearse social behavior and communication skills, which, may help them improve interaction with offline, face-to-face, social environments.

Stress and psychological well-being among allied health professionals

This study reports findings of an online survey of 139 health professionals. Health professionals were asked about the degree and type of workplace stress they encountered, as well as general perceived stress, psychological distress, and life satisfaction. The sample comprised social workers, psychologists, occupational therapists, physiotherapists, speech pathologists, and a small number of other allied health professionals. The allied health professional groups were remarkably similar in terms of workplace stress, life satisfaction, perceived stress outside the workplace, and the depression, anxiety, and stress subscales of the Depression Anxiety and Stress Scale. There were no significant differences in these variables between those working in hospital and community settings. Compared with expectations based on normative data, more people in the present sample had Depression Anxiety and Stress Scale depression scores in the mild, moderate, severe, or very severe range. The single significant predictor of psychological distress and life satisfaction was perceived stress. In the context of an increasingly generic health care workforce, the present findings indicate that workplace stressors are also generic and that generic, interdisciplinary stress management approaches may therefore be recommended.

Iron-rich silicates in the Earth's D'' layer

High-pressure experiments and theoretical calculations demonstrate that an iron-rich ferromagnesian silicate phase can be synthesized at the pressure-temperature conditions near the core-mantle boundary. The iron-rich phase is up to 20% denser than any known silicate at the core-mantle boundary. The high mean atomic number of the silicate greatly reduces the seismic velocity and provides an explanation to the low-velocity and ultra-low-velocity zones. Formation of this previously undescribed phase from reaction between the silicate mantle and the iron core may be responsible for the unusual geophysical and geochemical signatures observed at the base of the lower mantle.

Randomised controlled crossover trial of humidified continuous positive airway pressure in mild obstructive sleep apnoea

BACKGROUND

It is unclear whether continuous positive airway pressure (CPAP), the treatment of choice for severe obstructive sleep apnoea (OSA), is effective at improving outcomes in mild OSA.

METHODS

To help define the role of humidified CPAP in mild OSA, a randomised crossover study was undertaken of patients with an apnoea hypopnoea index (AHI) of 5-30/hour. Subjective sleepiness, objective wakefulness, mood, reaction time, and quality of life were measured at baseline, after 3 weeks treatment with humidified CPAP and 3 weeks sham CPAP (2 week washout).

RESULTS

Twenty nine of 31 enrolled patients (age 25-67 years, seven women, mean (SD) body mass index 31.5 (6) kg/m2) completed the protocol. Humidified CPAP improved polysomnographic indices of OSA and Epworth Sleepiness Scale (2.4 points (95% CI 0.6 to 4.2)). Objective wakefulness (modified maintenance of wakefulness test) showed a trend towards improvement (5.2 minutes (95% CI -0.6 to 11)). Mood (Hospital Anxiety and Depression Scale), quality of life (SF 36, Functional Outcomes of Sleep Questionnaire), and reaction times (Psychomotor Vigilance Task) were not improved more than sham CPAP. Compliance with humidified and sham CPAP both averaged 4.9 hours/night. Placebo effects were evident in many outcomes and there was no clear treatment preference.

CONCLUSIONS

Humidified CPAP improves subjective sleepiness and possibly objective wakefulness but not reaction times, quality of life, or mood. These results do not support the routine use of CPAP in all patients with mild OSA, but offers some support for the trialling of CPAP in those with severe sleepiness.

Ferromagnesian postperovskite silicates in the D'' layer of the Earth

Natural olivine with 12 mol % Fe(2)SiO(4) and synthetic orthopyroxenes with 20% and 40% FeSiO(3) were studied beyond the pressure-temperature conditions of the core-mantle boundary. All samples were found to convert entirely or partially into the CaIrO(3) postperovskite structure, which was recently reported for pure MgSiO(3). The incorporation of Fe greatly reduces the pressure needed for the transition and establishes the new phase as the major component of the D'' layer. With the liquid core as an unlimited reservoir of iron, core-mantle reactions could further enrich the iron content in this phase and explain the intriguing seismic signatures observed in the D'' layer.

Favourable outcome for patients with myeloid disorders treated with fludarabine-melphalan reduced-intensity conditioning and allogeneic bone marrow stem cell transplantation without the use of T-lymphocyte-depleting antibodies

We report the use of reduced-intensity conditioning (RIC)-matched sibling allogeneic bone marrow stem cell transplantation as a method of establishing a graft-vs.-leukaemia (GvL) effect against myeloid disorders using a fludarabine-melphalan protocol without the use of T-lymphocyte-depleting antibodies. The 16 patients in this group had predominantly poor-risk acute myeloid leukaemia (AML) (n=10), AML/myelodysplasia (MDS) (n=2) and MDS (n=4). All but one patient achieved full haematopoietic engraftment. Thirteen of 16 patients are alive and in continued complete remission on completion of this study with a median follow-up of 426 d (range 83-1524). The actuarial 4 yr disease-free and overall survival is 79% for both. Only one patient relapsed following transplant, giving a relapse rate of 6% during the study period. The treatment-related mortality was 13% (n= 2). Overall, acute graft-vs.-host disease (GvHD) occurred in 53% (8/15), with acute GvHD grade II or above occurring in 47% (7/15). In the 13 evaluable patients, chronic GvHD occurred in 46% (6/13), with this being extensive in three patients. These results suggest that a GvL effect can be delivered against poor-risk myeloid disorders with a low non-relapse mortality using this fludarabine-melphalan RIC protocol.

Fractal characteristics of breath to breath timing in sleeping infants

We examined interbreath interval (IBI) time series of 19 term infants during active and quiet sleep for fractal properties using Fano factor analysis. For each time series we calculated the fractal exponent (alpha), comparing alpha for the original time series with two forms of surrogate data, a temporally independent surrogate set and an autoregressive surrogate set. alpha values were normally distributed between 0.79 and -0.22, and did not differ with sleep state. The fractal characteristics of the original time series were not retained in the temporally independent surrogate time series indicating that the distribution of intervals alone was not fractal, but were retained using autoregressive surrogates with an order of 10, suggesting that the fractal properties of the IBI time series were related to correlations between successive breaths. These observations suggest that some of the respiratory variability that occurs during sleep in infants, which in the past has been regarded as stochastic noise, may be the product of deterministic processes.

Humidified nasal continuous positive airway pressure in obstructive sleep apnoea

Heated humidification of nasal continuous positive airway pressure (nCPAP) reduces upper airway symptoms and improves initial use in obstructive sleep apnoea syndrome (OSAS). The present study aimed to assess the effect of heated humidification of nCPAP on upper airway symptoms and initial use in obstructive sleep apnoea. This study was of a randomised, crossover design. Subjects with polysomnographically confirmed OSAS were randomised to 3 weeks nCPAP treatment with heated humidification (nCPAP-humid) or placebo humidification (nCPAP pl-humid). Objective and subjective nCPAP use, upper airway symptoms, and treatment satisfaction were compared. Thirty seven of 42 patients completed the protocol. nCPAP-humid reduced the frequency of adverse upper airway symptoms. nCPAP use over 3 weeks was greater with nCPAP-humid compared with nCPAP pl-humid. No difference was found between the treatment arms in terms of subjective treatment satisfaction or alertness. Heated humidification of nasal continuous positive airway pressure reduces upper airway symptoms and is associated with a small increase in initial use but not subjective sleepiness or treatment satisfaction. The results support the use of heated humidification as a strategy to reduce side-effects related to continuous positive airway pressure but not routine initial use.

Iron-silicon alloy in Earth's core?

We have investigated the phase relations in the iron-rich portion of the iron-silicon (Fe-Si) alloys at high pressures and temperatures. Our study indicates that Si alloyed with Fe can stabilize the body-centered cubic (bcc) phase up to at least 84 gigapascals (compared to approximately 10 gigapascals for pure Fe) and 2400 kelvin. Earth's inner core may be composed of hexagonal close-packed (hcp) Fe with up to 4 weight percent Si, but it is also conceivable that the inner core could be a mixture of a Si-rich bcc phase and a Si-poor hcp phase.