Observation of the effect of gravity on the motion of antimatter

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production

The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.

Short-Term Concerns Primarily Determine Patient Preference for Abdominal Aortic Aneurysm Repair

INTRODUCTION

Abdominal aortic aneurysm (AAA) repair may be performed through open or endovascular approaches, but the factors influencing a patient's repair-type preference are not well characterized. Here we performed a qualitative analysis to better understand factors influencing patient preference within the Preference for Open Versus Endovascular Repair of AAA Trial.

METHODS

Open-ended responses regarding primary (n = 21) and secondary (n = 47) factors influencing patient preference underwent qualitative analysis using the constant comparative method with iterative reviews. Codes were used to generate themes and themes grouped into categories, with each step conducted via consensus agreement between three researchers. Relative prevalence of themes were compared to ascertain trends in patient preference.

RESULTS

Patient responses regarding both primary and secondary factors fell into four categories: Short-term concerns, long-term concerns, advice & experience, and other. Patients most frequently described short-term concerns (23) as their primary influence, with themes including post-op complications, hospitalization & recovery, and intraoperative concerns. Long-term concerns were more prevalent (20) as secondary factors, which included themes such as survival, and chronic management. The average age of patients voicing only long-term concerns as a primary factor was 11 years younger than those listing only short-term concerns.

CONCLUSION

Short-term concerns relating to the procedure and recovery are more often the primary factor influencing patient preference, while long term concerns play a more secondary role. Long-term concerns are more often a primary factor in younger patients. Vascular surgeons should consider this information in shared decision making to reach an optimal outcome.

Hematology/medical oncology fellow responses to the initial development of an antiracism curriculum

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Background: While the American Council on Graduate Medical Education (ACGME) set up a Planning Committee for Diversity in GME in 2018, no formalized milestones or training mandates have been announced. The nation-wide protests for racial justice following the senseless killings of Breonna Taylor, Ahmaud Arbery and George Floyd further brought to the forefront the need for immediate action to address widespread inequities across graduate medical education, our healthcare system and society as a whole. Therefore, the Johns Hopkins Hematology/Medical Oncology Fellowship Program focused on creating an anti-racism curriculum to foster dialogue on systemic racism and discrimination, grounded in the institutional and geographic context of our training program. Methods: Using the Kern six step curriculum development method, we created a comprehensive anti-racism initiative, which included virtual townhalls with Black alumni of the fellowship, book clubs, readings, and lectures. We sought to deepen the fellowship’s awareness of the impact of racism and inequity upon trainees, underrepresented minority oncologists and hematologists, and patients in order to develop initiatives to confront them productively. Trainees received a survey 6 months after the start of the curriculum to assess the impact of the initiatives upon trainees, and inform iterative changes to the curriculum. Results: 25 of 34 fellows across all post-graduate years (PGY) completed the survey. Fellows agreed that the curriculum was helpful (68%) and encouraging (60%). Collectively, fellows reported that the curriculum increased their awareness of instances of racism in medicine, caused them to think about next steps that the fellowship could take to address racism, and enabled them to identify available resources for support and further education. Respondents selected community engagement and recruitment of diverse fellowship classes as the most pressing priorities for the program. Conclusions: Social justice and anti-racism education belong in the formalized training of our hematology/medical oncology fellows. To this end, our ongoing curricular expansion is focusing on anti-racism training, diverse recruitment and youth mentorship. Collectively, a comprehensive yet program-specific approach facilitates opportunities for learning, engagement and development of the skills necessary to engage in this life-long work for ourselves, our communities and our patients.

Laser cooling of antihydrogen atoms

The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6-8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11-13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.

The most influential papers in mitral valve surgery; a bibliometric analysis

This study is an analysis of the 100 most cited articles in mitral valve surgery. A bibliometric analysis is a tool to evaluate research performance in a given field. It uses the number of times a publication is cited by others as a proxy marker of its impact. The most cited paper Carpentier et al. discusses mitral valve repair in terms of restoring the geometry of the entire valve rather than simply narrowing the annulus (Carpentier, J Thorac Cardiovasc Surg 86:23–37, 1983). The first successful mitral valve repair was performed by Elliot Cutler at Brigham and Women’s Hospital in 1923 (Cohn et al., Ann Cardiothorac Surg 4:315, 2015). More recently percutaneous and minimally invasive techniques that were originally designed as an option for high risk patients are being trialled in other patient groups (Hajar, Heart Views 19:160–3, 2018). Comparison of percutaneous method with open repair represents an expanding area of research (Hajar, Heart Views 19:160–3, 2018). This study will analyse the top 100 cited papers relevant to mitral valve surgery, identifying the most influential papers that guide current management, the institutions that produce them and the authors involved.

Abstract PD6-01: Prevalence and predictors of self-reported memory ability in a large sample of breast cancer survivors

Background: A substantial subset of women previously treated for breast cancer report deficits in cognitive abilities such as memory. Cancer-related cognitive dysfunction (CRCD) has been linked to a variety of factors including chemotherapy. However, the reported prevalence of symptoms is variable and investigations of CRCD correlates in large samples are limited. This study aimed to 1) investigate whether the prevalence of patient-reported memory problems differs as a function of having received chemotherapy and time-since-treatment; and 2) identify additional factors associated with patient-reported memory in a large sample of breast cancer survivors.

Method: In this cross-sectional cohort study, self-administered questionnaires including those assessing memory (Multifactorial Memory Questionnaire) and lifestyle behaviors were mailed to 1500 disease-free breast cancer survivors from three time-since-treatment cohorts (early: 6-18 months, middle: 2-4 years, or late: 5-12 years post-treatment). Demographic and clinical information was collected and confirmed from chart review. The prevalence of clinically significant memory dysfunction was estimated using published normative cut-off scores. We tested whether chemotherapy and time-since-treatment affected memory (analysis of variance), or increased the risk of significant memory dysfunction (odds ratio chi-squared test). Using a forward stepwise regression model, we explored whether patient characteristics (age, education, comorbidities, concussion history, adverse life events), type of treatment (chemotherapy, radiotherapy, hormonal therapy), or lifestyle behaviors (adherence to a Mediterranean diet, physical activity, sleep efficiency, stress management practices) were associated with patient-reported memory.

Results: 773 questionnaire packages were returned (mean age=60.4±11.7). 436 (56%) survivors had received chemotherapy (Ch+), and 337 (44%) had not (Ch-). 314 (41%) were early survivors, 244 (32%) were middle, and 215 (28%) were late. Ch+ reported poorer memory than Ch- (F(1, 764)=12.752, p<0.001), with no effect of time-since-treatment or interaction. Prevalence of significant memory dysfunction was higher in Ch+ (28%) than in Ch- (15%) (OR=2.130, 95% CI 1.479-3.066). Younger age and history of concussion were significantly associated with worse patient-reported memory (p=0.002, p<0.001). Unlike chemotherapy (p=0.018), neither radiation nor hormonal treatment was a significant predictor of memory symptoms. Increased physical activity (p=0.002) and higher sleep efficiency (p<0.001) were associated with better memory. Survivors reporting greater memory symptoms also reported greater use of stress management techniques (p=0.026).

Conclusion: This large study indicates that chemotherapy doubles the risk of memory symptoms up to at least 10 years post-treatment. Results also point to sleep hygiene and physical activity as potentially meaningful targets for self-management training to reduce CRCD in breast cancer survivors.

Citation Format: Bernstein LJ, D'Amico DN, Richard NM, McCready DR, Howell D, Jones JM, Edelstein K. Prevalence and predictors of self-reported memory ability in a large sample of breast cancer survivors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-01.

Exploring cancer centres for physical activity and sedentary behaviour support for breast cancer survivors

Background

Up to 90% of breast cancer survivors report low levels of physical activity (pa) and spend approximately 70% of the day in sedentary behaviour. Survivors might not be receiving information about the health benefits of pa and the consequences of sedentary behaviour in the context of their cancer. The primary purpose of the present study was to evaluate cancer centres for pa and sedentary behaviour information and infrastructure. A secondary aim was to evaluate the quality of the information that is accessible to breast cancer survivors in cancer centres.

Methods

A built-environment scan of the 14 regional cancer centres in Ontario and an evaluation of the text materials about pa available at the cancer centres were completed. Data analyses included descriptive statistics, proportions, and inter-rater reliability.

Results

The infrastructure of the cancer centres provided few opportunities for dissemination of information related to pa through signs and printed notices. Televisions were present in all waiting rooms, which could provide a unique opportunity for dissemination of information about pa and sedentary behaviour. Text materials were rated as trustworthy, used some behaviour change techniques (for example, information about the consequences of lack of pa, barrier identification, and setting graded tasks), and were aesthetically pleasing.

Conclusions

These findings represent areas for knowledge dissemination both for the centre and for resources that could be further improved.

Observation of the 1S-2P Lyman-α transition in antihydrogen

In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.

Characterization of the 1S-2S transition in antihydrogen

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.

Connecting people with cancer to physical activity and exercise programs: a pathway to create accessibility and engagement

Recent guidelines concerning exercise for people with cancer provide evidence-based direction for exercise assessment and prescription for clinicians and their patients. Although the guidelines promote exercise integration into clinical care for people with cancer, they do not support strategies for bridging the guidelines with related resources or programs. Exercise program accessibility remains a challenge in implementing the guidelines, but that challenge might be mitigated with conceptual frameworks ("pathways") that connect patients with exercise-related resources. In the present paper, we describe a pathway model and related resources that were developed by an expert panel of practitioners and researchers in the field of exercise and rehabilitation in oncology and that support the transition from health care practitioner to exercise programs or services for people with cancer. The model acknowledges the nuanced distinctions between research and exercise programming, as well as physical activity promotion, that, depending on the available programming in the local community or region, might influence practitioner use. Furthermore, the pathway identifies and provides examples of processes for referral, screening, medical clearance, and programming for people after a cancer diagnosis. The pathway supports the implementation of exercise guidelines and should serve as a model of enhanced care delivery to increase the health and well-being of people with cancer.

Socioeconomic status and lifestyle behaviours in cancer survivors: smoking and physical activity

PURPOSE

Smoking cessation and increased physical activity (pa) have been linked to better outcomes in cancer survivors. We assessed whether socioeconomic factors influence changes in those behaviours after a cancer diagnosis.

METHODS

As part of a cross-sectional study, a diverse group of cancer survivors at the Princess Margaret Cancer Centre (Toronto, ON), completed a questionnaire about past and current lifestyle behaviours and perceptions about the importance of those behaviours with respect to their health. The influence of socioeconomic indicators on smoking status and physical inactivity at 1 year before and after diagnosis were assessed using multivariable logistic regression with adjustment for clinico-demographic factors.

RESULTS

Of 1222 participants, 1192 completed the smoking component. Of those respondents, 15% smoked before diagnosis, and 43% of those smokers continued to smoke after. The proportion of survivors who continued to smoke increased with lower education level (p = 0.03). Of the 1106 participants answering pa questions, 39% reported being physically inactive before diagnosis, of whom 82% remained inactive afterward. Survivors with a lower education level were most likely to remain inactive after diagnosis (p = 0.003). Lower education level, household income, and occupation were associated with the perception that pa had no effect or could worsen fatigue and quality of life (p ≤ 0.0001).

CONCLUSIONS

In cancer survivors, education level was a major modifier of smoking and pa behaviours. Lower socioeconomic status was associated with incorrect perceptions about pa. Targeting at-risk survivors by education level should be evaluated as a strategy in cancer survivorship programs.

Effects of fludarabine treatment on murine lupus nephritis

BXSB mice, a murine model of systemic lupus erythematosus (SLE), were treated with two different doses of fludarabine for a four-week period and examined two weeks after the final dose. Control mice were treated with saline or cyclophosphamide. Mice treated with fludarabine had a significant reduction in renal pathology compared to control mice. Fludarabine-treated mice also had an almost 10-fold increase in percentile of CD8+CD25+ T cells in the spleen and a smaller but significant increase in CD4+CD25+ cells. Mice treated with cyclophosphamide had a greater leucopenia compared to the other groups and a significant reduction in percentile of B220+ cells in peripheral blood and spleen. Serum autoantibody levels to dsDNA did not differ significantly among the groups, but were higher in 4/10 mice treated with fludarabine. Although few trials of fludarabine for human SLE have been conducted, additional studies may be warranted.

The use of conservation biomass feedstocks as potential bioenergy resources in the United Kingdom

A number of countries have introduced energy policies to reduce the emission of carbon dioxide which, in the case of bio-heat, has resulted in increased use of small wood burning stoves and boilers, particularly in Europe. There are issues surrounding the supply of sustainable wood feedstock, prompting a desire to utilise local biomass resources. This includes biomass generated through the management of natural woodlands in nature reserves and conservation areas. These management practices can also extend to other areas, such as raised bog wildernesses and estuary Reed beds. We term the biomass from this resource as conservation biomass. This study is concerned with the viability of this resource as a fuel within the United Kingdom, and combustion tests were carried out using a small domestic stove. It was concluded that there is as much as 500kty(-1) that could be used in this way.

Frequency Comparison of [Formula: see text] Ion Optical Clocks at PTB and NPL via GPS PPP

We used precise point positioning, a well-established GPS carrier-phase frequency transfer method to perform a direct remote comparison of two optical frequency standards based on single laser-cooled [Formula: see text] ions operated at the National Physical Laboratory (NPL), U.K. and the Physikalisch-Technische Bundesanstalt (PTB), Germany. At both institutes, an active hydrogen maser serves as a flywheel oscillator which is connected to a GPS receiver as an external frequency reference and compared simultaneously to a realization of the unperturbed frequency of the (2)S1/2(F=0)-(2)D3/2(F=2) electric quadrupole transition in [Formula: see text] via an optical femtosecond frequency comb. To profit from long coherent GPS-link measurements, we extrapolate the fractional frequency difference over the various data gaps in the optical clock to maser comparisons which introduces maser noise to the frequency comparison but improves the uncertainty from the GPS-link instability. We determined the total statistical uncertainty consisting of the GPS-link uncertainty and the extrapolation uncertainties for several extrapolation schemes. Using the extrapolation scheme with the smallest combined uncertainty, we find a fractional frequency difference [Formula: see text] of -1.3×10(-15) with a combined uncertainty of 1.2×10(-15) for a total measurement time of 67 h. This result is consistent with an agreement of the frequencies realized by both optical clocks and with recent absolute frequency measurements against caesium fountain clocks within the corresponding uncertainties.

High Risk Aortic Valve Replacement - The Challenges of Multiple Treatment Strategies with an Evolving Technology

OBJECTIVES

Deciding on the optimal treatment strategy for high risk aortic valve replacement is challenging. Transcatheter Aortic Valve implantation (TAVI) has been available in our centre as an alternative treatment modality for patients since 2008. We present our early experience of TAVI and SAVR (surgical Aortic Valve Replacement) in high risk patients who required SAVR because TAVI could not be performed.

METHODS

The database for Surgical aortic valve and Transcatheter aortic valve replacement referrals was interrogated to identify relevant patients.

RESULTS

Survival to hospital discharge was 95.5% in the forty five patients who had SAVR when TAVI was deemed technically unsuitable. One year survival was 86%.

CONCLUSION

Defining who is appropriate for TAVI or high risk SAVR is challenging and multidisciplinary team discussion has never been more prudent in this field of evolving technology with ever decreasing risks of surgery. The introduction of TAVI at our institution has seen a rise in our surgical caseload by approximately by 25%. Overall, the option of aortic valve intervention is being offered to more patients in general which is a substantial benefit in the treatment of aortic valve disease.

Bone health management in men undergoing ADT: examining enablers and barriers to care

The study determined prostate cancer specialists' knowledge and concordance to guidelines regarding the diagnosis, management, and prevention of androgen deprivation therapy-induced osteoporosis. Despite high knowledge regarding bone health, most respondents did not routinely measure bone mineral density or use fracture risk assessment tools, suggesting a significant gap in the screening/monitoring of bone health.

INTRODUCTION

The purpose of this study was to determine prostate cancer specialists' knowledge, practices, self-perceived competencies and barriers to providing guideline-concordant care in the diagnosis, prevention, and management of androgen deprivation therapy (ADT)-induced osteoporosis (OP).

METHODS

A number of 73 Canadian radiation oncologists and 83 urologists completed questionnaires assessing (i) knowledge regarding OP and consensus guidelines for bone health management in men receiving ADT, (ii) self-assessed competencies regarding bone health management, (iii) current practices regarding OP prevention and management, and (iv) self-perceived barriers to providing guideline-concordant care.

RESULTS

The majority of respondents were able to correctly identify the guideline-concordant frequency of repeat dual-energy X-Ray absorptiometry (DXA) scans (76.3%), vitamin D (70.3%), and calcium (53.2%) intake and that bisphosphonates/denosumab should always be considered for patients with a history of one low-trauma fracture (57.6%). Just under 1/3 (32.5%) reported routinely measuring bone mineral density (BMD) prior to starting ADT and routinely measuring BMD 1-2 years following the initiation of ADT (36.6%). Only 4.6% of respondents routinely used a validated fracture risk assessment tool. Lowest self-assessed competency levels were reported in providing self-management education to patients to foster the uptake of healthy bone behaviors (HBBs) and managing patients who present with or develop osteopenia and OP. The most significant barriers to providing OP prevention and management were lack of time and lack of supporting structures.

CONCLUSIONS

Despite high knowledge about appropriate bone health care among prostate cancer specialists, there remain significant gaps in screening and monitoring of bone health, suggesting the need to develop innovative strategies to overcome barriers to implementation.

Hydrogen from ethanol reforming with aqueous fraction of pine pyrolysis oil with and without chemical looping

Reforming ethanol ('EtOH') into hydrogen rich syngas using the aqueous fraction from pine bio-oil ('AQ') as a combined source of steam and supplementary organic feed was tested in packed bed with Ni-catalysts 'A' (18wt%/α-Al2O3) and 'B' (25wt%/γ-Al2O3). The catalysts were initially pre-reduced by H2, but this was followed by a few cycles of chemical looping steam reforming, where the catalysts were in turn oxidised in air and auto-reduced by the EtOH/AQ mixture. At 600°C, EtOH/AQ reformed similarly to ethanol for molar steam to carbon ratios (S/C) between 2 and 5 on the H2-reduced catalysts. At S/C of 3.3, 90% of the carbon feed converted on catalyst A to CO2 (58%), CO (30%) and CH4 (2.7%), with 17wt% H2 yield based on dry organic feedstock, equivalent to 78% of the equilibrium value. Catalyst A maintained these outputs for four cycles while B underperformed due to partial reduction.

Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants

Singly ionized ytterbium, with ultranarrow optical clock transitions at 467 and 436 nm, is a convenient system for the realization of optical atomic clocks and tests of present-day variation of fundamental constants. We present the first direct measurement of the frequency ratio of these two clock transitions, without reference to a cesium primary standard, and using the same single ion of 171Yb+. The absolute frequencies of both transitions are also presented, each with a relative standard uncertainty of 6×10(-16). Combining our results with those from other experiments, we report a threefold improvement in the constraint on the time variation of the proton-to-electron mass ratio, μ/μ=0.2(1.1)×10(-16)  yr(-1), along with an improved constraint on time variation of the fine structure constant, α/α=-0.7(2.1)×10(-17)  yr(-1).

Combustion and gasification characteristics of chars from raw and torrefied biomass

Torrefaction is a mild thermal pretreatment (T<300°C) that improves biomass milling and storage properties. The impact of torrefaction on the gasification and oxidation reactivity of chars from torrefied and raw biomass was investigated. Thermogravimetric analysis was used to study the differences in O(2) and steam reactivity, between chars prepared from torrefied and raw willow, under both high- and low-heating-rate conditions. High-heating-rate chars were prepared at 900°C with a residence time of 2s. Low-heating-rate chars were prepared with a heating rate of 33°C/min, a maximum temperature of 850 or 1000°C, and a residence time of 30 min or 1h, respectively, at the maximum temperature. Pretreatment by torrefaction consistently reduced char reactivity. Torrefaction's impact was greatest for high-heating-rate chars, reducing reactivity by a factor of two to three. The effect of torrefaction on a residence time requirements for char burnout and gasification was estimated.

Co-administration of morphine and oxycodone vaccines reduces the distribution of 6-monoacetylmorphine and oxycodone to brain in rats

Opioid conjugate vaccines have shown promise in animal models as a potential treatment for opioid addiction. Individual vaccines are quite specific and each targets only a limited number of structurally similar opioids. Since opioid users can switch or transition between opioids, we studied a bivalent immunization strategy of combining 2 vaccines that could target several of the most commonly abused opioids; heroin, oxycodone and their active metabolites. Morphine (M) and oxycodone (OXY) haptens were conjugated to keyhole limpet hemocyanin (KLH) through tetraglycine (Gly)(4) linkers at the C6 position. Immunization of rats with M-KLH alone produced high titers of antibodies directed against heroin, 6-monoacetylmorphine (6-MAM) and morphine. Immunization with OXY-KLH produced high titers of antibodies against oxycodone and oxymorphone. Immunization with the bivalent vaccine produced consistently high antibody titers against both immunogens. Bivalent vaccine antibody titers against the individual immunogens were higher than with the monovalent vaccines alone owing, at least in part, to cross-reactivity of the antibodies. Administration of a single concurrent intravenous dose of 6-MAM and oxycodone to rats immunized with the bivalent vaccine increased 6-MAM, morphine and oxycodone retention in serum and reduced the distribution of 6-MAM and oxycodone to brain. Vaccine efficacy correlated with serum antibody titers for both monovalent vaccines, alone or in combination. Efficacy of the individual vaccines was not compromised by their combined use. Consistent with the enhanced titers in the bivalent group, a trend toward enhanced pharmacokinetic efficacy with the bivalent vaccine was observed. These data support the possibility of co-administering two or more opioid vaccines concurrently to target multiple abusable opioids without compromising the immunogenicity or efficacy of the individual components.

Neuronal expression of Fig4 is both necessary and sufficient to prevent spongiform neurodegeneration

FIG4 is a ubiquitously expressed phosphatase that, in complex with FAB1/PIKFYVE and VAC14, regulates the biosynthesis of the signaling lipid PI(3,5)P(2). Null mutation of Fig4 in the mouse results in spongiform degeneration of brain and peripheral ganglia, defective myelination and juvenile lethality. Partial loss-of-function of human FIG4 results in a severe form of Charcot-Marie-Tooth neuropathy. Neurons from null mice contain enlarged vacuoles derived from the endosome/lysosome pathway, and astrocytes accumulate proteins involved in autophagy. Other cellular defects include astrogliosis and microgliosis. To distinguish the contributions of neurons and glia to spongiform degeneration in the Fig4 null mouse, we expressed Fig4 under the control of the neuron-specific enolase promoter and the astrocyte-specific glial fibrillary acidic protein promoter in transgenic mice. Neuronal expression of Fig4 was sufficient to rescue cellular and neurological phenotypes including spongiform degeneration, gliosis and juvenile lethality. In contrast, expression of Fig4 in astrocytes prevented accumulation of autophagy markers and microgliosis but did not prevent spongiform degeneration or lethality. To confirm the neuronal origin of spongiform degeneration, we generated a floxed allele of Fig4 and crossed it with mice expressing the Cre recombinase from the neuron-specific synapsin promoter. Mice with conditional inactivation of Fig4 in neurons developed spongiform degeneration and the full spectrum of neurological abnormalities. The data demonstrate that expression of Fig4 in neurons is necessary and sufficient to prevent spongiform degeneration. Therapy for patients with FIG4 deficiency will therefore require correction of the deficiency in neurons.

Survey of women veterinarians in New Zealand Part I: Patterns of work

A survey was undertaken to ascertain the extent to which women veterinarians in New Zealand were employing their veterinary skills, and to identify some of the factors which affect women;s ability or choice to work full-time in their profession. Replies were received from 115 of 140 women registered by the New Zealand Veterinary Surgeons Board. Women in full-time veterinary employment at the time of the survey made up 63% of the sample, 19% were employed part-time, and 18% were not working. Women with children on average had worked as veterinary surgeons proportionately less time since qualification than either single women or women with no children. Women with children worked in their profession for a significantly greater proportion of time if they had both emotional and physical support in the home. Women who employed paid household help were in a minority in the sample. The distribution of women in different fields of veterinary employment was similar to that of a similar sized sample of men. The main reasons women gave for reducing their work level were pregnancy and lactation, difficulties in combining professional work with family commitments, a desire to spend time with children at home, and difficulty in finding a suitable position.

Dwarfism in Hereford cattle: a genetic morphological and biochemical study

A study of 40 Hereford cattle dwarfs in New Zealand confirmed that dwarfism in this country was morphologically the same as that described in North American Herefords and that its mode of inheritance was as an autosomal recessive trait. The histological architecture of growth plates was essentially normal but palisading columns were shorter and more irregular than in controls. A small proportion of chondrocytes in dwarf cartilage showed increased areas of cytoplasmic metachromasia, which probably coincided with increased cystic dilations of endoplasmic reticulum containing granular material as noted by electronmicroscopy. The above growth-plate abnormalities were neither prominent nor consistent enough to be of diagnostic significance; nor do they currently help understanding of the underlying pathogenic mechanism of dwarfing. Histological and mucopolysaccharide excretion studies unequivocally demonstrated that this disease is not a mucopolysaccharidosis as had previously been reported.

Intestinal lymphangiectasia in a dog

An eight-month-old female crossbred terrier was presented with a short history of diarrhoea, dyspnoea and abdominal distension. Clinical examination revealed thoracic effusion, ascites, and subcutaneous oedema. Hypoalbuminaemia, hypoglobulinaemia and lymphopaenia were all present. Histological examination of a jejunal biopsy confirmed a diagnosis of intestinal Iymphangiectasia. Full clinical recovery followed treatment by dietary management.

Seasonal variation in the chemical composition of the bioenergy feedstock Laminaria digitata for thermochemical conversion

To avoid negative impacts on food production, novel non-food biofuel feedstocks need to be identified and utilised. One option is to utilise marine biomass, notably fast-growing, large marine 'plants' such as the macroalgal kelps. This paper reports on the changing composition of Laminaria digitata throughout it growth cycle as determined by new technologies. The potential of Laminaria sp. as a feedstock for biofuel production and future biorefining possibilities was assessed through proximate and ultimate analysis, initial pyrolysis rates using thermo-gravimetric analysis (TGA), metals content and pyrolysis gas chromatography-mass spectrometry. Samples harvested in March contained the lowest proportion of carbohydrate and the highest ash and alkali metal content, whereas samples harvested in July contained the highest proportions of carbohydrate, lowest alkali metals and ash content. July was therefore considered the most suitable month for harvesting kelp biomass for thermochemical conversion to biofuels.

Effects of streptococcal cell wall fragments on phagocytosis and tissue culture cells

Group A streptococcal cell wall fragments inhibited phagocytosis of unrelated particles by rabbit polymorphonuclear leukocytes and inhibited the growth of rabbit kidney cells in vitro. Activity was associated with the mucopeptide moiety. Whole streptococci or the cytoplasmic fraction were less effective than cell wall fragments. The cell wall fragments of group D streptococci, Bacillus megaterium, and Escherichia coli were inactive. The inhibition of phagocytosis illustrates one way in which microbial components may influence the immune response. The toxicity for tissue cultures of rabbit kidney cell monolayers was greatest during the phase of active cell division. This appears to be a direct toxic effect of cell wall fragments on mammalian cells and may be related to the in vivo injury previously reported for streptococcal cell walls.

Production of shelf-stable ranch dressing using high-pressure processing

High-pressure processing (HPP) can reduce or eliminate microorganisms of concern in food without deteriorating product quality; however, quality benefits must justify the substantial capital investment for the utilization of this technology. HPP is particularly a beneficial preservation technology for products damaged by thermal treatments or when product quality could be improved by reformulation to raise pH or eliminate chemical preservatives. The primary objectives of this study were to determine the efficacy of HPP to protect premium ranch dressing (pH 4.4) from microbial spoilage and to assess changes in physical, chemical, and sensory attributes throughout the product's shelf life. In inoculated-packages studies, the efficacy of HPP was measured against ranch dressing spoilage organisms: Pediococcus acidilactici, Lactobacillus brevis, and Torulaspora delbrueckii. HPP treatment (600 MPa, 3 min) decreased population of P. acidilactici, the most pressure-resistant spoilage organism tested, by >or= 6.4 log CFU/g. During a shelf-life study of edible product, treating ranch dressing at 600 MPa for 5 min effectively prevented microbial spoilage throughout the storage period (26 wk at 4 and 26 degrees C). The pH and emulsion stability of ranch dressing were not adversely influenced by HPP. Extended storage of HPP product for 16 to 26 wk at 26 degrees C resulted in a decrease in consumer acceptance and significant changes in color and organic acid profile (specifically, increased pyroglutamic acid). These changes were consistent with those expected during extended storage of commercially available products. HPP may be used to produce premium ranch dressing, with defined shelf-life and storage conditions, without significantly changing product attributes.

Long-term follow-up after non-myeloablative transplant of bone and marrow in BXSB mice

We present long-term outcomes of BXSB mice after non-myeloablative bone marrow transplants using major histocompatability complex (MHC)-matched cells. Groups differed in sources of donor lymphocytes or mesenchymal stromal cells (MSC). Unfractionated marrow cells from green fluorescent protein (GFP) transgenic (Tg) mice (BMT group) or from RAG1−/− B6 mice (RAG group) were injected intravenously (i.v.) into irradiated (550 cGy) hosts. As a source of mesenchymal cells, bone chips from GFP-Tg were injected intraperitoneally alone (MSC group) or along with i.v. bone marrow cells (BMT + MSC group). Controls were untreated mice (UnTx) or mice exposed to radiation only (Rad Cont). At 62 weeks post-transplant, surviving mice were harvested for histopathology, flow cytometry and real time polymerase chain reaction (RT-PCR). The mice from BMT + MSC group had the best outcomes for survival rates (71.4% vs. 43.8%), renal scores (2.9% vs. 28.8% glomerular sclerosis) and percent splenic monocytes (4.2 vs. 11.3%) compared with mice from Rad Cont. Improvement in RAG and BMT groups was less prominent but were comparable with one another. Although MSC alone were not sufficient to control the renal pathology, it limited the expansion of CD4−CD8− T cell populations without a change in Foxp3 expression. The results suggest the importance of the innate immune system in disease pathogenesis and a role for MSC in immunomodulation.

FTIR spectroscopic analysis of sputum: preliminary findings on a potential novel diagnostic marker for COPD

COPD is a common, progressively disabling disease and a major health burden worldwide. Fourier transform infrared (FTIR) spectroscopy provides for sensitive analysis of complex biological samples. COPD pathogenesis involves quantitative and qualitative changes in sputum biosynthesis. This first study explores whether FTIR can produce distinct spectral profiles of human sputum, and capture differences between COPD and health. Sputum obtained from 15 COPD patients and 15 healthy volunteers was analysed using FTIR spectroscopy; differences in peak positions, height and configuration were identified and measured. All samples gave reproducible characteristic IR absorption spectra. The most relevant regions identified were the amide and glycogen rich regions, showing crucial spectral differences between health and COPD relating to peak position shifts or intensity alteration. These novel preliminary findings support further exploration of FTIR sputum profiling in a clinical study to determine its potential as a practical method for monitoring COPD.

Classification of macroalgae as fuel and its thermochemical behaviour

A preliminary classification of five macroalgae from the British Isles; Fucus vesiculosus, Chorda filum, Laminaria digitata, Fucus serratus, Laminaria hyperborea, and Macrocystis pyrifera from South America, has been presented in terms of a Van Krevelen diagram. The macroalgae have been characterised for proximate and ultimate analysis, inorganic content, and calorific value. The different options for thermal conversion and behaviour under combustion and pyrolysis have been evaluated and compared to several types of terrestrial biomass including Miscanthus, short rotation Willow coppice and Oat straw. Thermal treatment of the macroalgae has been investigated using thermogravimetry (TGA) and pyrolysis-gc-ms. Combustion behaviour is investigated using TGA in an oxidising atmosphere. The suitability of macroalgae for the different thermal processing routes is discussed. Ash chemistry restricts the use of macroalgae for direct combustion and gasification. Pyrolysis produces a range of pentosans and a significant proportion of nitrogen containing compounds. High char yields are produced.

Detection of astrovirus in the faeces of cats with diarrhoea

Examination by electron microscopy of faeces from two separate cases of young cats with diarrhoea revealed the presence of 28 nm viral particles morphologically consistent with an astrovirus. No visible cytopathic effect was observed when the virus was inoculated into a feline kidney cell culture.

Adenoviral gene transfer to the heart during cardiopulmonary bypass: effect of myocardial protection technique on transgene expression

OBJECTIVE

Adenoviral gene transfer to the arrested heart during cardiopulmonary bypass (CPB) is a novel method of allowing prolonged vector contact with the myocardium. In this model we investigated the importance of temperature, duration of arrest and cardioplegia on transgene expression.

METHODS

First-generation adenoviral vector (1 x 10(12) total viral particles) containing the transgene for the human beta2-adrenoceptor (Adeno-beta(2)AR) or beta-galactosidase (Adeno-beta(gal)) was delivered to neonatal piglets via the proximal aorta, during simulated cardiac surgery, and allowed to dwell for the cross-clamp duration. Four treatment groups received Adeno-beta(2)AR. Groups A (n=4) and B (n=6) underwent cold crystalloid cardioplegia arrest for 10 and 30 min, respectively, Group C (n=5) underwent warm crystalloid cardioplegia arrest for 10 min, and Group D (n=5) underwent warm fibrillatory arrest for 10 min. Group E (n=6) received Adeno-beta(gal) and underwent cold crystalloid cardioplegia arrest (30 min). Animals were weaned off CPB and recovered for 2 days. Receptor density was assessed in membrane fractions using radioligand binding and compared using the Mann-Whitney U-test.

RESULTS

Left ventricular transgene overexpression, as evidenced by elevated betaAR density, following Adeno-beta(2)AR treatment was greatest with cold cardioplegia (Group A 588+/-288.8 fmol/mg; P=0.002 and Group B 520+/-250.9 fmol/mg; P=0.01) versus control (Group E 109+/-8.4 fmol/mg). Overexpression also occurred with warm cardioplegia (Group C 274+/-69.5 fmol/mg; P=0.05) and ventricular fibrillation (Group D 215+/-48.4 fmol/mg; P=0.02) versus control. Comparison of the combined cold cardioplegia groups versus those treated with warm conditions showed a trend towards increased expression with cold conditions (P=0.1). Receptor density was also significantly increased in the right ventricle of animals in Group B (165+/-18.1 fmol/mg; P=0.03) and Group D (181+/-23.4 fmol/mg; P=0.02) versus control (Group E 118+/-5.8 fmol/mg).

CONCLUSIONS

Cold crystalloid cardioplegia is not detrimental to gene transfer in vivo. In fact, there was a trend towards increased left ventricular transgene expression when the adenoviral vector was delivered following cold versus warm cardioplegia. Shorter periods of contact with the vector may reduce transgene overexpression. Therefore, gene transfer is possible during cardiac surgery with clinically used myocardial protection techniques.

Candida parapsilosis: two cases of endocarditis in association with the Toronto stentless porcine valve

Candida parapsilosis endocarditis in association with prosthetic heart valves is rare. We report the first two cases of C. parapsilosis endocarditis on the Toronto stentless porcine valve (TSPV) and the first reported case of successful elimination of infection without lifelong antifungal therapy.

A study of the reaction of oxygen with graphite: model chemistry

A considerable amount of research has been directed towards the mechanism of oxidation of graphite as a model reaction system and because of its industrial importance. A number of recent studies have been concerned with ab initio molecular orbital calculations on graphite including model chemistry and the reactions with molecular oxygen. This study is concerned with oxidation steps involving the attachment of molecular oxygen to the graphene, the formation of carbon monoxide and, in particular, the subsequent oxidation reactions.

Intermediates in V(D)J recombination: a stable RAG1/2 complex sequesters cleaved RSS ends

Rearrangement of gene segments to generate antigen receptor coding regions depends on the RAG1/2 recombinase, which assembles a synaptic complex between two DNA signal sequences and then cleaves the DNA directly adjacent to the paired signals. After coupled cleavage of complementary signal sequences, virtually all of the cleaved signal ends remained associated with RAG1/2 in stable complexes. These signal end complexes were distinct from various precleavage RAG1/2 signal complexes in that they were resistant to treatment with heparin. A mammalian joining apparatus consisting of purified Ku70/86, XRCC4, and DNA ligase IV proteins was sufficient to join deproteinized cleaved ends, but retention of signal sequences within the signal end complex blocked access to the DNA ends and prevented their joining by these proteins. Sequestration of cleaved ends within the signal end complex would account for the persistence of these ends in the cell after cleavage and may explain why they do not normally activate the DNA-damage-dependent cell cycle checkpoint.

Correlating cell cycle with apoptosis in a cell line expressing a tandem green fluorescent protein substrate specific for group II caspases

BACKGROUND

We describe a rapid flow cytometric assay that correlates cell cycle with apoptotic cell death in a cell line expressing a tandem green fluorescent protein (GFP).

METHODS

A Jurkat cell line was transfected with a gene construct coding for constitutive expression of a tandem GFP molecule carrying a consensus cleavage site (DEVD) for group II caspases (C-2-Y). Cells were treated with CD95 antibody (Ab), then incubated with annexin V-phycoerythrin (PE), propidium iodide (PI), and Hoechst 33342.

RESULTS

After CD95 treatment, the C-2-Y cell line had twice the number of nonapoptotic cells compared with both control cell lines. This proportion of viable, nonapoptotic cells after treatment was unaffected by the level of GFP (DEVD) expression in the cells, as confirmed by sorted populations. The early apoptotic cells in the C-2-Y cell line had an increased G0-G1 phase population compared with the control cell lines.

CONCLUSIONS

Apoptosis is delayed in the C-2-Y cell line and the early apoptotic cells have a higher G0-G1 cell cycle frequency. The artificial substrate competes with the natural substrate(s), thereby slowing the apoptotic process. The expression level of DEVD-GFP does not alter the delayed induction of apoptosis. Caspase activation occurs prior to phosphatidylserine translocation.

Repeat heart valve surgery: risk factors for operative mortality

BACKGROUND

Patients undergoing repeat heart valve operations are a diverse population. We assessed risk factors for operative mortality in patients undergoing a first heart valve reoperation.

METHODS

A retrospective review of hospital records was performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998. Univariable and multivariable analyses were performed.

RESULTS

Operative mortality was 8.6%. Mortality fell each decade to 4.8% in the most recent period (adjusted chi(2) for linear trend P <.0005). Mortality increased from 3.0% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis. Concomitant coronary artery bypass grafting was associated with a mortality of 15.4% compared with 8.2% when it was not required. Mortality for aortic valve replacement was 6.4%, mitral valve replacement 7.4%, aortic and mitral valve replacement 11.5%, tricuspid valve replacement 25.6%, periprosthetic leak repair 9.1%, and isolated valve repair 2.2%. Among 336 patients requiring replacement of prosthetic valves, mortality was 26.1% for replacement of a mechanical valve compared with 8.6% for replacement of a tissue valve (P <.0005). Multivariable analyses identified year of reoperation, age, coronary artery bypass grafting, indication, and replacement of a mechanical valve rather than a tissue valve as significant explanatory variables for operative mortality.

CONCLUSIONS

Heart valve reoperations can be performed with an acceptable operative mortality. However, we have identified several categories of patients in whom reoperation carries an increased risk.

Escherichia coli PriA helicase: fork binding orients the helicase to unwind the lagging strand side of arrested replication forks

Escherichia coli PriA is a primosome assembly protein with 3' to 5' helicase activity whose apparent function is to promote resumption of DNA synthesis following replication-fork arrest. Here, we describe how initiation of helicase activity on DNA forks is influenced by both fork structure and by single-strand DNA-binding protein. PriA could recognize and unwind forked substrates where one or both arms were primarily duplex, and PriA required a small (two bases or larger) single-stranded gap at the fork in order to initiate unwinding. The helicase was most active on substrates with a duplex lagging-strand arm and a single-stranded leading-strand arm. On this substrate, PriA was capable of translocating on either the leading or lagging strands to unwind the duplex ahead of the fork or the lagging-strand duplex, respectively. Fork-specific binding apparently orients the helicase domain to unwind the lagging-strand duplex. Binding of single-strand-binding protein to forked templates could inhibit unwinding of the duplex ahead of the fork but not unwinding of the lagging-strand duplex or translocation on the lagging-strand template. While single-strand-binding protein could inhibit binding of PriA to the minimal, unforked DNA substrates, it could not inhibit PriA binding to forked substrates. In the cell, single-strand-binding protein and fork structure may direct PriA helicase to translocate along the lagging-strand template of forked structures such that the primosome is specifically assembled on that DNA strand.

A Ku bridge over broken DNA

The Ku heterodimer is essential for the nonhomologous end-joining pathway of DNA double-strand break repair; it both protects the broken ends and recruits some of the many proteins required to complete repair. The recently determined structure of Ku provides insights into how it can both bind to the DNA ends and allow access by the other proteins required to rejoin them.

Disordered eating attitudes and behaviours in teenaged girls: a school-based study

BACKGROUND

Disordered eating attitudes and behaviours are common in older teens and young women in Western countries. Recent evidence suggests that the prevalence of these disorders is rising and that the age of onset has fallen. In the present study, disturbed eating attitudes and behaviours were evaluated in a large school-based population in Ontario in order to determine their prevalence and demographic distribution.

METHODS

Females, aged 12-18 years, from schools in Toronto, Hamilton and Ottawa were invited to complete questionnaires, including 3 subscales of the Eating Disorder Inventory (Drive for Thinness, Body Dissatisfaction, Bulimia), the Eating Attitudes Test-26 (EAT-26) and the Diagnostic Survey for Eating Disorders (DSED).

RESULTS

Questionnaires were completed by 1739 (70%) of the 2483 adolescent females who were approached. The mean age of subjects in the sample was 14.6 (standard deviation 1.9) years. Thirteen percent of those aged 12-14 years and 16% of those aged 15-18 years had scores above the recommended cut-off (> or = 20) for disordered eating on the EAT-26. Current dieting to lose weight was reported by 23% of participants. Binge eating with associated loss of control was reported by 15% of participants, self-induced vomiting by 8.2% and the use of diet pills by 2.4%. Laxative and diuretic misuse were uncommon. Dieting was associated with an increased risk of binge-eating and purging behaviours. Older age and body mass index in the highest quartile were independently related to symptoms of eating disorders.

INTERPRETATION

Disordered eating attitudes and behaviours were present in over 27% of girls aged 12-18 years and were seen to increase gradually throughout adolescence. Prevention programs to diminish the progression and impact of these disorders should be implemented and assessed.

More than just a pamphlet: development of an innovative computer-based education program for cancer patients

Patients with cancer continue to lack practical information regarding their illness and report low levels of awareness and use of patient services. The challenge to educators is to find cost-effective and timely ways to deliver a complex mix of interesting and high-quality information and expertise to this large and diverse audience, while still tailoring the content to individual needs and situations. In the present article, we describe the Princess Margaret Hospital (PMH) computer-based patient education program. The program is aimed toward empowering those dealing with cancer and provides comprehensive medical information and support via an interactive Intranet web site containing information about cancer (the Oncology Interactive Education Series), library resources, Internet links, information about PMH services, and a hospital calendar of events. Preliminary evaluation results have provided valuable direction for on-going program development and suggest that the program is easy to use, informative, and enjoyable for patients, families, volunteers, and health professionals.

Guidelines for evaluating tools for clinical decision making

Managed care is designed to reduce healthcare costs by controlling use of services and by improving quality outcomes. Preparation of nurses to practice in a health management environment mandates clear understanding of this new environment Nursing educators should focus on the spectrum of health services and enhance the nurses'ability to assess patients independently, implement health plans, and be responsible for outcomes. Nurses must understand how clinical decision-making tools facilitate planning care to maximize use of resources. The authors describe the construction and evaluation of a learning strategy that involves the use of guidelines to evaluate clinical decision-making tools. Two examples are presented: evaluating clinical pathways in a case management project and evaluating algorithm (practice guideline) outcome data from a prenatal population case study from a local health maintenance organization.