Effective Field Theories on the Jet Bundle

We develop a generalized field space geometry for higher-derivative scalar field theories, expressing scattering amplitudes in terms of a covariant geometry on the all-order jet bundle. The incorporation of spacetime and field derivative coordinates solves complications due to higher-order derivatives faced by existing approaches to field space geometry. We identify a jet bundle analog to the field space metric that, besides field redefinitions, exhibits invariance under total derivatives. The invariance consequently extends to its amplitude contributions and the canonical covariant geometry.

On-Shell Covariance of Quantum Field Theory Amplitudes

Scattering amplitudes in quantum field theory are independent of the field parametrization, which has a natural geometric interpretation as a form of "coordinate invariance." Amplitudes can be expressed in terms of Riemannian curvature tensors, which makes the covariance of amplitudes under nonderivative field redefinitions manifest. We present a generalized geometric framework that extends this manifest covariance to all allowed field redefinitions. Amplitudes satisfy a recursion relation to all orders in perturbation theory that closely resembles the application of covariant derivatives to increase the rank of a tensor. This allows us to argue that tree-level amplitudes possess a notion of "on-shell covariance," in that they transform as a tensor under any allowed field redefinition up to a set of terms that vanish when the equations of motion and on-shell momentum constraints are imposed. We highlight a variety of immediate applications to effective field theories.

The muon Smasher's guide

We lay out a comprehensive physics case for a future high-energy muon collider, exploring a range of collision energies (from 1 to 100 TeV) and luminosities. We highlight the advantages of such a collider over proposed alternatives. We show how one can leverage both the point-like nature of the muons themselves as well as the cloud of electroweak radiation that surrounds the beam to blur the dichotomy between energy and precision in the search for new physics. The physics case is buttressed by a range of studies with applications to electroweak symmetry breaking, dark matter, and the naturalness of the weak scale. Furthermore, we make sharp connections with complementary experiments that are probing new physics effects using electric dipole moments, flavor violation, and gravitational waves. An extensive appendix provides cross section predictions as a function of the center-of-mass energy for many canonical simplified models.

Supersoft Top Squarks

In a supersymmetric theory, the IR contributions to the Higgs mass are calculable below the mediation scale Λ_{UV} in terms of the IR field content and parameters. However, logarithmic sensitivity to physics at Λ_{UV} remains. In this Letter, we present a first example of a framework, dictated by symmetries, to supersoften these logarithms from the matter sector. The result is a model with finite, IR-calculable corrections to the Higgs mass. This requires the introduction of new fields-the "lumberjacks"-whose role is to screen the UV-sensitive logs. These models have considerably reduced fine-tuning, by more than an order of magnitude for high-scale supersymmetry. This impacts interpretations of the natural parameter space, suggesting it may be premature to declare a naturalness crisis for high-scale supersymmetry.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Long-lived particles at the energy frontier: the MATHUSLA physics case

We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the [Formula: see text]m scale up to the Big Bang Nucleosynthesis limit of [Formula: see text] m. Neutral LLPs with lifetimes above [Formula: see text]100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.

Exponential Hierarchies from Anderson Localization in Theory Space

We present a new mechanism for generating exponential hierarchies in four-dimensional field theories inspired by Anderson localization in one dimension, exploiting an analogy between the localization of electron energy eigenstates along a one-dimensional disordered wire and the localization of mass eigenstates along a local "theory space" with random mass parameters. Mass eigenstates are localized even at arbitrarily weak disorder, with exponentially suppressed couplings to sites in the theory space. The mechanism is quite general and may be used to exponentially localize fields of any spin. We apply the localization mechanism to two hierarchies in standard model parameters-the smallness of neutrino masses and the ordering of quark masses-and comment on the possible relevance to the electroweak hierarchy problem. This raises the compelling possibility that some of the large hierarchies observed in and beyond the standard model may result from disorder, rather than order.

Health Status following Major Trauma in the West of Scotland: Pilot Descriptive Study

Background

Data on the long-term outcome of major trauma survivors in the United Kingdom (UK) is lacking. This pilot study aimed to investigate the health status of survivors of major trauma without significant head injury in the West of Scotland, and to compare the Short-Form 12 (SF12) questionnaire administered by telephone (TSF12) to the longer Short-Form 36 (SF36) questionnaire.

Methods

This was a descriptive, comparative, pilot clinical study. Eligible patients had an injury severity score (ISS) >15, sustained their injuries >2 years ago, abbreviated injury score (AIS) <2 for head trauma and were treated in two Glasgow hospitals. The Short-Form 36 (SF36) health status questionnaire was completed at home, and the Short-Form 12 (SF12) questionnaire was administered by telephone (TSF12).

Results

From 141 eligible patients (85% male, median age 35 years, median ISS 19 and median Ps 0.981), 13 patients completed the study. Despite small numbers, mean SF36 scores were significantly lower in four dimensions compared to UK means. SF36 summary scores were non-significantly below US and UK means. The TSF12 physical summary score was significantly below US and UK means. Correlations between the SF36 and TSF12, and SF12 intra-class correlations were high. One-way ANOVA showed significantly lower mental summary scores for patients with spinal injuries.

Conclusions

This small study suggests that non-head injured survivors of major trauma have lower health status than the UK average. The TSF12 appears to be a practical alternative to the conventional SF36 and warrants larger scale evaluation.

A facility to search for hidden particles at the CERN SPS: the SHiP physics case

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, [Formula: see text] and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals-scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.

Explaining trends in alcohol-related harms in Scotland 1991-2011 (II): policy, social norms, the alcohol market, clinical changes and a synthesis

OBJECTIVE

To provide a basis for evaluating post-2007 alcohol policy in Scotland, this paper tests the extent to which pre-2007 policy, the alcohol market, culture or clinical changes might explain differences in the magnitude and trends in alcohol-related mortality outcomes in Scotland compared to England & Wales (E&W).

STUDY DESIGN

Rapid literature reviews, descriptive analysis of routine data and narrative synthesis.

METHODS

We assessed the impact of pre-2007 Scottish policy and policy in the comparison areas in relation to the literature on effective alcohol policy. Rapid literature reviews were conducted to assess cultural changes and the potential role of substitution effects between alcohol and illicit drugs. The availability of alcohol was assessed by examining the trends in the number of alcohol outlets over time. The impact of clinical changes was assessed in consultation with key informants. The impact of all the identified factors were then summarised and synthesised narratively.

RESULTS

The companion paper showed that part of the rise and fall in alcohol-related mortality in Scotland, and part of the differing trend to E&W, were predicted by a model linking income trends and alcohol-related mortality. Lagged effects from historical deindustrialisation and socio-economic changes exposures also remain plausible from the available data. This paper shows that policy differences or changes prior to 2007 are unlikely to have been important in explaining the trends. There is some evidence that aspects of alcohol culture in Scotland may be different (more concentrated and home drinking) but it seems unlikely that this has been an important driver of the trends or the differences with E&W other than through interaction with changing incomes and lagged socio-economic effects. Substitution effects with illicit drugs and clinical changes are unlikely to have substantially changed alcohol-related harms: however, the increase in alcohol availability across the UK is likely to partly explain the rise in alcohol-related mortality during the 1990s.

CONCLUSIONS

Future policy should ensure that alcohol affordability and availability, as well as socio-economic inequality, are reduced, in order to maintain downward trends in alcohol-related mortality in Scotland.

Explaining trends in alcohol-related harms in Scotland, 1991-2011 (I): the role of incomes, effects of socio-economic and political adversity and demographic change

OBJECTIVE

This paper tests the extent to which differing trends in income, demographic change and the consequences of an earlier period of social, economic and political change might explain differences in the magnitude and trends in alcohol-related mortality between 1991 and 2011 in Scotland compared to England & Wales (E&W).

STUDY DESIGN

Comparative time trend analyses and arithmetic modelling.

METHODS

Three approaches were utilised to compare Scotland with E&W: 1. We modelled the impact of changes in income on alcohol-related deaths between 1991-2001 and 2001-2011 by applying plausible assumptions of the effect size through an arithmetic model. 2. We used contour plots, graphical exploration of age-period-cohort interactions and calculation of Intrinsic Estimator coefficients to investigate the effect of earlier exposure to social, economic and political adversity on alcohol-related mortality. 3. We recalculated the trends in alcohol-related deaths using the white population only to make a crude approximation of the maximal impact of changes in ethnic diversity.

RESULTS

Real incomes increased during the 1990s but declined from around 2004 in the poorest 30% of the population of Great Britain. The decline in incomes for the poorest decile, the proportion of the population in the most deprived decile, and the inequality in alcohol-related deaths, were all greater in Scotland than in E&W. The model predicted less of the observed rise in Scotland (18% of the rise in men and 29% of the rise in women) than that in E&W (where 60% and 68% of the rise in men and women respectively was explained). One-third of the decline observed in alcohol-related mortality in Scottish men between 2001 and 2011 was predicted by the model, and the model was broadly consistent with the observed trends in E&W and amongst women in Scotland. An age-period interaction in alcohol-related mortality was evident for men and women during the 1990s and 2000s who were aged 40-70 years and who experienced rapidly increasing alcohol-related mortality rates. Ethnicity is unlikely to be important in explaining the trends or differences between Scotland and E&W.

CONCLUSIONS

The decline in alcohol-related mortality in Scotland since the early 2000s and the differing trend to E&W were partly described by a model predicting the impact of declining incomes. Lagged effects from historical social, economic and political change remain plausible from the available data.

Neutral naturalness from orbifold Higgs models

We present a general class of natural theories in which the Higgs boson is a pseudo-Goldstone boson in an orbifolded gauge theory. The symmetry protecting the Higgs boson at low energies is an accidental global symmetry of the quadratic action, rather than a full continuous symmetry. The lightest degrees of freedom protecting the weak scale carry no standard model (SM) quantum numbers and interact with visible matter principally through the Higgs portal. This opens the door to the systematic study of "neutral naturalness": natural theories with SM-neutral states that are as yet untested by the LHC.

New probe of naturalness

Any new scalar fields that perturbatively solve the hierarchy problem by stabilizing the Higgs boson mass also generate new contributions to the Higgs boson field-strength renormalization, irrespective of their gauge representation. These new contributions are physical, and in explicit models their magnitude can be inferred from the requirement of quadratic divergence cancellation; hence, they are directly related to the resolution of the hierarchy problem. Upon canonically normalizing the Higgs field, these new contributions lead to modifications of Higgs couplings that are typically great enough that the hierarchy problem and the concept of electroweak naturalness can be probed thoroughly within a precision Higgs boson program. Specifically, at a lepton collider this can be achieved through precision measurements of the Higgs boson associated production cross section. This would lead to indirect constraints on perturbative solutions to the hierarchy problem in the broadest sense, even if the relevant new fields are gauge singlets.

Can primary care be both patient-centred and community-led?

Examines the relationships between the macro-, meso-, and micro-levels in the NHS at the end of the fundholding period and considers their contemporary implications for primary care groups (PCGs) and local health care co-operatives (LHCCs). Fundholding achieved some success in challenging the way in which services were provided at the micro-level (the practice), but had a less marked effect in terms of changing service provision at the health authority (meso-) level or in developing collaborative working with trusts and health authorities in strategic decision making. The health authorities prioritized alternative models of devolved commissioning. Trusts regarded fundholders as a distraction who exerted influence and commanded trust management time disproportionate to their "market share". PCGs and LHCCs represent a shift back to the meso-level in service planning and purchasing. As such there is a risk that the micro-level benefits of fundholding and other forms of devolved commissioning will be lost, while uncertainties remain regarding the capacity of PCGs and LHCCs to incorporate GPs into a collaborative approach to strategic decision making.

Distraction lengthening of the radius for radial longitudinal instability after distal radio-ulnar subluxation and excision of the radial head: a case report

The results of late surgery for symptomatic proximal migration of the radius after resection of the radial head for trauma are usually disappointing. Ulnar variance increases when the interosseous membrane is disrupted. Its integrity should be assessed to predict the results of further surgery. We describe a 29-year-old patient in whom distraction lengthening of the radius through an Ilizarov frame allowed him to regain pain-free function of the wrist and elbow after a complex Essex-Lopresti fracture dislocation and late symptoms of ulnar carpal impingement.

Relationship between dynamical and equilibrium characteristics of glass-forming polymeric liquids

A connection between measurable equilibrium thermodynamic quantities and a nonequilibrium property of supercooled polymeric liquids, namely, the fragility index, is proposed within the framework of a synthesis of generalized configurational entropy models. The theoretical predictions are compared with experimental data on five glass-forming polymers.

Randomised trial of personalised computer based information for patients with schizophrenia

OBJECTIVES

To compare use, effect, and cost of personalised computer education with community psychiatric nurse education for patients with schizophrenia.

DESIGN

Randomised trial of three interventions. Modelling of costs of alternatives.

PARTICIPANTS

112 patients with schizophrenia in contact with community services; 67 completed the intervention.

INTERVENTIONS

Three interventions of five educational sessions: (a) computer intervention combining information from patient's medical record with general information about schizophrenia; (b) sessions with a community psychiatric nurse; (c) "combination" (first and last sessions with nurse and remainder with computer).

MAIN OUTCOME MEASURES

Patients' attendance, opinions, change in knowledge, and psychological state; costs of interventions and patients' use of NHS community services; modelling of costs for these three, and alternative, interventions.

RESULTS

Rates of completion of intervention did not differ significantly (71% for combination intervention, 61% for computer only, 46% for nurse only). Computer sessions were shorter than sessions with nurse (14 minutes v 60 minutes). More patients given nurse based education thought the information relevant. Of 20 patients in combination group, 13 preferred the sessions with the nurse and seven preferred the computer. There were no significant differences between groups in psychological outcomes. Because of the need to transport patients to the computer for their sessions, there was no difference between interventions in costs, but computer sessions combined with other patient contacts would be substantially cheaper.

CONCLUSIONS

The computer based patient education offered no advantage over sessions with a community psychiatric nurse. Investigation of computer use combined with other health service contacts would be worth while.

Measuring the costs and benefits of heart disease monitoring

OBJECTIVE

To evaluate the costs and benefits of alternative systems of coronary heart disease monitoring in Scotland.

DESIGN

An option appraisal was conducted to evaluate the costs and benefits of implementing a coronary heart disease monitoring system. This involved a review of existing Scottish datasets and relevant reports, specification of options, definition and weighting of benefit criteria by key stakeholders, assessment of options by experts, and costing of options. The options were assessed by 33 stakeholders (grouped as cardiologists, patient representatives, general practitioners, public health physicians, and policy makers), plus 13 topic experts.

SETTING

Scotland (population 5.1 million).

RESULTS

Between group mean benefit weights were: mortality rates and case fatality (10.6), quality of life (9.8), patient function (8.8), hospital activity (7.8), primary care activity (9.25), prescribing (5.72), socioeconomic impact (4.0), risk factors (7.4), prevalence (5.0), incidence (6.0), case registration (6.82), international comparability (4.2), breadth of coverage (8.8), and frequency (5.8). Differences between group weights were significant for prevalence (p = 0.048) and international comparability (p = 0.032). Four monitoring options were identified: a community epidemiology model, based on MONICA (monitoring trends and determinants in cardiovascular disease) study methodology applied to a series of eight representative communities, had the highest benefits, at an average annual discounted cost of approximately pound 360,000; models based on the Australian cardiovascular disease monitoring scheme and on enhanced routine data offered fewer benefits at discounted average annual costs ranging from pound 165,000 to pound 195,000; finally, a coronary heart disease registry modelled on the Scottish Cancer Registry scheme would have had fewer benefits and substantially higher costs than the other options.

CONCLUSIONS

The most beneficial coronary heart disease monitoring system is the community epidemiology model, based on MONICA methodology. Option appraisal potentially offers an explicit and transparent methodology for evidence based policy development.

Randomised trial of personalised computer based information for cancer patients

OBJECTIVE

To compare the use and effect of a computer based information system for cancer patients that is personalised using each patient's medical record with a system providing only general information and with information provided in booklets.

DESIGN

Randomised trial with three groups. Data collected at start of radiotherapy, one week later (when information provided), three weeks later, and three months later.

PARTICIPANTS

525 patients started radical radiotherapy; 438 completed follow up.

INTERVENTIONS

Two groups were offered information via computer (personalised or general information, or both) with open access to computer thereafter; the third group was offered a selection of information booklets.

OUTCOMES

Patients' views and preferences, use of computer and information, and psychological status; doctors' perceptions; cost of interventions.

RESULTS

More patients offered the personalised information said that they had learnt something new, thought the information was relevant, used the computer again, and showed their computer printouts to others. There were no major differences in doctors' perceptions of patients. More of the general computer group were anxious at three months. With an electronic patient record system, in the long run the personalised information system would cost no more than the general system. Full access to booklets cost twice as much as the general system.

CONCLUSIONS

Patients preferred computer systems that provided information from their medical records to systems that just provided general information. This has implications for the design and implementation of electronic patient record systems and reliance on general sources of patient information.

Cloning, expression, and physical mapping of the 3beta-hydroxysteroid dehydrogenase gene cluster (HSD3BP1-HSD3BP5) in human

Seven members of the human 3beta-hydroxysteroid dehydrogenase (3beta-HSD) gene family (HGMW-approved symbols HSD3BP1-HSD3BP5) have been cloned and physically mapped. HSD3B1 and 2 express 3beta-HSD enzymes; HSD3Bpsi1-5 are unprocessed pseudogenes that are closely related to HSD3B1 and 2 but contain no corresponding open reading frames. mRNA is expressed from psi4 and psi5 in several tissues, but with altered splice sites that disrupt reading frames. A 0.5-Mb contig of 3 yeast artificial chromosome and 32 bacterial artificial chromosome genomic clones contained no additional members of the gene family. The seven genes and pseudogenes mapped within 230 kb in the order HSD3Bpsi5-psi4-psi3-HSD3B1-psi1-psi2 -HSD3B2. HSD3B1 and 2 are in direct repeat, 100 kb apart. Six HSD3B2 mutations involve substitutions that are present in several of the pseudogenes. In four cases, mutations arose in CpG sites that are conserved within the gene cluster. The tendency for CpG sites to mutate by transition provides an adequate explanation for these HSD3B2 mutations, which are unlikely to be due to recombination or conversion within the gene family.

Measuring progress towards a primary care-led NHS

BACKGROUND

The push towards a 'primary care-led' National Health Service (NHS) has far-reaching implications for the future structure of the NHS. The policy involves both a growing emphasis on the role of primary care practitioners in the commissioning of health services, and a change from hospital to primary and community settings for a range of services and procedures. Although the terminology has changed, this emphasis remains in the recent Scottish Health Service White Paper and its English counterpart.

AIM

To consider three questions in relation to this policy goal. First, does the evidence base support the changes? Secondly, what is the scale of the changes that have occurred? Thirdly, what are the barriers to the development of a primary care-led NHS?

METHOD

Programme budgets were compiled to assess changes over time in the balance of NHS resource allocation with respect to primary and secondary care. Total NHS revenue expenditure for the 15 Scottish health boards was grouped into four blocks or 'programmes': primary care, secondary care, community services, and a residual. The study period was 1991/2 to 1995/6. Expenditure data were supplied by the Scottish Office.

RESULTS

Ambiguity of definitions and the absence of good data cause methodological difficulties in evaluating the scale and the appropriateness of the shift. The data that are available suggest that, at the aggregate level, there have been changes over time in the balance of resource allocation between care settings: relative investment into primary care has increased. It would appear that this investment is relatively small and from growth money rather than a 'shift' from secondary care. In addition, the impact of GP-led commissioning is variable but limited.

CONCLUSION

General practitioners' (GPs') attitudes to the policy suggest that progress towards a primary care-led NHS will continue to be patchy. The limited shift to date, alongside evidence of ambivalent attitudes to the shift on the part of GPs, suggest that this is a policy objective that may not be achieved.

Computer simulation to estimate the effectiveness of carotid endarterectomy

OBJECTIVES

To investigate the benefit of carotid endarterectomy relative to medical treatment, by comparing the outcome for different groups of patients following transient ischaemic attacks.

METHODS

A Markov model was used to describe the survival and quality of life of patients treated for a transient ischaemic attack. The benefit is measured in terms of quality adjusted life months (QALMs). The outcome was estimated using a computer simulation with parameters based on published studies on the probability of events following treatment. The benefit of carotid endarterectomy was explored using a baseline set of parameters and a sensitivity analysis.

RESULTS

The baseline scenario of a 65-year-old male patient with the model factors set at an intermediate level showed a benefit for surgery of 3 QALMs compared with medical treatment alone. The sensitivity analysis showed that the most favourable combination of factors had a benefit of 13.4 QALMs and the least favourable a loss of 2 QALMs. Of all 128 factor combinations, 79.9% showed a benefit for surgery, 5.5% showed equal benefit, and 15.6% showed a benefit for medical treatment.

CONCLUSIONS

Computer simulations have the potential for deriving estimates of benefit for different patient groups from the results of clinical trials. Combined with reliable information on costs, the technique could also demonstrate variations in cost-effectiveness for these groups. For patients following a transient ischaemic attack, the results from this simulation and limited cost information suggest that carotid endarterectomy is unlikely to be a cost-effective intervention in the UK for many patient groups despite a reduction in the risk of stroke.

Less fog on the Tyne? Programme budgeting in Newcastle and North Tyneside

Programme Budgeting (PB) has been widely promoted as a model for the better conduct of the work of Health Authorities in the National Health Service in the United Kingdom. This paper reports on a project which looked at the development of PB in Newcastle and North Tyneside Health Authority (NNTHA), concentrating on the construction of a computerised tool for the compilation and analysis of programme budgets. The main activities carried out were a survey of user requirements for PB, a survey of data availability, the collection of data to construct programme budgets, and development of a relational database for storing and manipulating PB information. The main source of data was the Contract Minimum Data Set, which was supplemented by data from a number of other sources to give comprehensive information on spending in NNTHA. Costed activity data were produced, which could be aggregated in a large number of ways, such as by care setting (inpatient, outpatient, community, general practice, etc.), disease group (ICD9 chapter headings), case mix (Healthcare Resource Groups) and socio-demographic variables (age/sex, locality of GPs practice).

Choice and accountability in health promotion: the role of health economics

Choices need to be made between competing uses of health care resources. There is debate about how these choices should be made, who should make them and the criteria upon which they should be made. Evaluation of health care is an important part of this debate. It has been suggested that the contribution of health economics to the evaluation of health promotion is limited, both because the methods and principles underlying economic evaluation are unsuited to health promotion, and because the political and cultural processes governing the health care system are more appropriate mechanisms for allocating health care resources than systematic economic analysis of the costs and benefits of different health care choices. This view misrepresents and misunderstands the contribution of health economics to the evaluation of health promotion. It overstates the undoubted methodological difficulties of evaluating health promotion. It also argues, mistakenly, that economists see economic evaluation as a substitute for the political and cultural processes governing health care, rather than an input to them. This paper argues for an economics input on grounds of efficiency, accountability and ethics, and challenges the critics of the economic approach to judge alternative mechanisms for allocating resources by the same criteria.

Clearing the fog on the Tyne: programme budgeting in Newcastle and North Tyneside Health Authority

When the internal market was introduced, the National Health Service Management Executive envisaged purchasing as a process by which contracts would be developed from information concerning current services, modified in the light of strategic purchasing objectives, epidemiological needs assessment and indicators of comparative performance and efficiency. Our concern in this paper is with the promotion of efficiency. We distinguish between three levels and, in particular, discuss how the programme budgeting and marginal analysis framework can be used in the promotion of efficiency at 'top-level' decision making. PB/MA can be used to give a focus to needs assessment and forge explicit links between individual contracts within a well defined health strategy. The objectives of the current research and development ongoing within Newcastle and North Tyneside Health Authority are outlined. The intention is to achieve programme budgeting which is more responsive to decision makers' needs and is consistent with the contracting cycle. However, a number of constraints are expected to impede development. They include transferability of national and international information; absence of local information on epidemiology, effectiveness and cost-effectiveness; limitations on the accuracy and precision of programme budgets; and whether purchasers make strategic decisions based on macro budgets. The contribution of each of these constraints is explored.

The limits of the possible: models of power supply and demand in cycling

This paper outlines a general strategy for mathematical modeling of cycling performance. This strategy involves formulating one expression describing the power available for external work from physiological sources. The variables used in this expression include maximal aerobic power (VO2max), fractional utilisation of VO2max, mechanical efficiency, maximal accumulated oxygen deficit, and the time constants relating to the expression of aerobic and anaerobic capacities. A second expression describing the power demand of cycling is then constructed. The variables used in this expression include the mass, projected frontal area and drag characteristics of the system, the coefficient of rolling resistance, environmental variables such as temperature, barometric pressure, relative humidity, wind speed and direction and the slope of the course. The two expressions are equated and solved using an iterative procedure. Two series of trials were used to assess the predictive accuracy of the model, one using track endurance performances and the other a 26 km road time-trial. The correlations between actual and predicted times have been excellent (0.92-0.95, p < or = 0.0001), with small mean differences (0-1.83% of mean performance time) and mean absolute differences (1.07-3.24%). The model allows us to make predictions about the effect of equipment changes and environmental factors, to compare performances under very different conditions, and to predict the limits of the possible in cycling performance. A range of options designed to improve cycling performance is described.

Processing of eukaryotic ribosomal RNA

In summary, it can be argued that the understanding of eukaryotic rRNA processing is no less important than the understanding of mRNA maturation, since the capacity of a cell to carry out protein synthesis is controlled, in part, by the abundance of ribosomes. Processing of pre-rRNA is highly regulated, involving many cellular components acting either alone or as part of a complex. Some of these components are directly involved in the modification and cleavage of the precursor rRNA, while others direct the packaging of the rRNA into ribosome subunits. As is the case for pre-mRNA processing, snoRNPs are clearly involved in eukaryotic rRNA processing, and have been proposed to assemble with other proteins into at least one complex called a "processosome" (17), which carries out the ordered processing of the pre-rRNA and its assembly into ribosomes. The formation of a processing complex clearly makes possible the regulation required to coordinate the abundance of ribosomes with the physiological and developmental changes of a cell. It may be that eukaryotic rRNA processing is even more complex than pre-mRNA maturation, since pre-rRNA undergoes extensive nucleotide modification and is assembled into a complex structure called the ribosome. Undoubtedly, features of the eukaryotic rRNA-processing pathway have been conserved evolutionarily, and the genetic approach available in yeast research (6) should provide considerable knowledge that will be useful for other investigators working with higher eukaryotic systems. Interestingly, it was originally hoped that the extensive work and understanding of bacterial ribosome formation would provide a useful paradigm for the process in eukaryotes. However, although general features of ribosome structure and function are highly conserved between bacterial and eukaryotic systems, the basic strategy in ribosome biogenesis seems to be, for the most part, distinctly different. Thus, the detailed molecular mechanisms for rRNA processing in each kingdom will have to be independently deciphered in order to elucidate the features and regulation of this important process for cell survival.

Lanterns in the jungle: is the NHS driven by the wrong kind of efficiency?

The performance of the National Health Service is assessed in part by an Efficiency Index (EI) which is applied to the service as a whole as well as to individual health authorities. The EI relates increases in the amount of patient care activity to increases in total expenditure. The index can give a misleading impression of performance, creates perverse incentives and is at odds with the overall strategy of the health service which is to place greater emphasis on the promotion of health and to provide more care in primary and community-based settings. The philosophy, validity and appropriateness of the EI are discussed.

Preferential transposition of Drosophila P elements to nearby chromosomal sites

Two different schemes were used to demonstrate that Drosophila P elements preferentially transpose into genomic regions close to their starting sites. A starting element with weak rosy+ marker gene expression was mobilized from its location in the subtelomeric region of the 1,300-kb Dp1187 minichromosome. Among progeny lines with altered rosy+ expression, a much higher than expected frequency contained new insertions on Dp1187. Terminal deficiencies were also recovered frequently. In a second screen, a rosy(+)-marked element causing a lethal mutation of the cactus gene was mobilized in male and female germlines, and viable revertant chromosomes were recovered that still contained a rosy+ gene due to an intrachromosomal transposition. New transpositions recovered using both methods were mapped between 0 and 128 kb from the starting site. Our results suggested that some mechanism elevates the frequency 43-67-fold with which a P element inserts near its starting site. Local transposition is likely to be useful for enhancing the rate of insertional mutation within predetermined regions of the genome.

Umbilical cord knots and encirclements

Although cord knots and/or encirclements account for 1 in 10 stillbirths of infants weighing 2,500 g or more, no problem due to this cause was encountered in a prospective study of 1,115 vaginal deliveries. In this study there were 6 cases of cord knot (0.5%) and 158 of cord encirclement (14.2%). The range of cord length was 27-122 cm, the 10th, 50th and 90th percentiles being 40, 52 and 69 cm respectively. In this study there was no clinical warning (fetal distress) of cord encirclement or knot during pregnancy, labour or delivery.

Primary processing of mammalian rRNA involves two adjacent cleavages and is not species specific

The primary transcript of the mouse rRNA gene is rapidly processed at nucleotide approximately +650 both in vivo and in vitro. Using run-off transcription in a mouse cell extract as well as S1 nuclease and primer extension analysis of cellular RNA, we demonstrated that this primary processing actually results in the formation of two species of downstream RNA which differ in length by approximately 6 nucleotides, indicating the existence of two closely positioned alternative processing sites. The 200-base-pair region just 3' to the mouse processing site has a striking 80% sequence homology with a region of the human rRNA external transcribed spacer, and S1 nuclease analysis of human cellular RNA has demonstrated that an analogous rRNA processing occurs at the 5' border of the homologous human region. Unlike rDNA transcriptional initiation, however, the primary rRNA processing is not highly species specific, for the transcript of a chimeric gene containing the human processing region adjacent to a mouse rDNA promoter was synthesized and correctly processed in a mouse cell extract. This result confirms that mouse and human rRNA undergo a common primary processing event which is evidently directed by sequences within the 200-base-pair conserved sequence region.

Nucleotide sequence determining the first cleavage site in the processing of mouse precursor rRNA

The first step in the processing of 47S precursor rRNA in mouse cells is reproduced in vitro in an S-100 transcription reaction and consists of an endonucleolytic cleavage at residue +650 of the primary transcript followed by rapid degradation of the fragment upstream from residue +650. An analogous processing occurs in human rRNA. The mouse and human rRNA sequences are approximately equal to 80% conserved for 200 nucleotides on the 3' side of these processing sites, suggesting that this conserved region may be important in specifying the processing. To test this hypothesis, we constructed a systematic series of deletion mutants approaching the mouse rDNA processing region from both the 5' and 3' directions and analyzed the processing of their transcripts in vitro. The 5' boundary of the region required for processing is quite sharp and corresponds to the rRNA cleavage site at the 5' end of the conserved sequence region. The 3' boundary is more complex: The 3' deletions extending to between 250 and 130 nucleotides beyond the processing site cause about a 50% decrease in the amount of the processed RNA. A 3' deletion that extends to 109 nucleotides beyond the processing site greatly reduces the processing efficiency. Deletions to or beyond 91 nucleotides on the 3' side of the processing site virtually eliminate processing. Under altered ionic conditions, transcripts of 3' deletions extending to only 41 nucleotides beyond the processing site can still direct a low level of accurate processing. These results demonstrate that the mouse/human conserved sequence just on the 3' side of the primary rRNA processing site consists of several domains that direct and/or augment both the initial endonucleolytic cleavage and the closely coupled selective degradation of the upstream fragment that together constitute the primary rRNA processing event.

Treatment of Chinese hamster ovary cells with the transcriptional inhibitor actinomycin D inhibits binding of messenger RNA to ribosomes

Inhibitors of RNA synthesis such as actinomycin D, MPB, and cordycepin progressively inhibit the initiation of protein synthesis in intact, nucleated mammalian cells. This inhibition is not dependent on the levels of mRNA, ribosomes, or tRNA. Lysates prepared from CHO cells treated with actinomycin D do not incorporate labeled globin mRNA or ovalbumin mRNA into 80S initiation complexes at the rates of untreated control extract. The ability of the extracts to produce and accumulate 48S preinitiation complexes was assessed using the 60S subunit joining inhibitors edeine and 5'-guanylyl imidodiphosphate. Control extracts were able to accumulate both the 48S preinitiation complexes and the migration-related intermediates in the presence of both inhibitors. However, lysates derived from CHO cells treated with actinomycin D were unable to produce these complexes. This was also true at low temperature, a condition that does not inhibit mRNA binding but prevents migration of the 43S complex along the mRNA. Mixing experiments with extracts from untreated control or AMD-treated CHO cells provided no evidence for a translational inhibitor. Thus, our data are consistent with the hypothesis that treatment of whole cells with actinomycin D inhibits protein synthesis initiation at the level of mRNA binding and not at migration or 60S subunit joining.

Inhibition of protein synthesis in CHO cells by actinomycin D: lesion occurs after 40S initiation complex formation

Inhibitors of RNA synthesis such as actinomycin D, 2-mercapto-1-(beta-4-pyridylethyl)benzimidazole, and cordycepin progressively inhibit the initiation of protein synthesis in intact nucleated mammalian cells independent of their effect on mRNA synthesis. The mechanism of this effect is unknown. The activity of cell-free lysates is not directly affected by these inhibitors, suggesting that their effect is indirect and requires an intact cell. However, lysates prepared from L-cells or CHO cells treated with the inhibitors do exhibit a decrease in initiation activity corresponding in magnitude to the effect seen in intact cells. Mixing experiments with lysates isolated from untreated or treated cells provide no evidence for a translational inhibitor. However, experiments analyzing the incorporation of [35S]methionine and [35S]Met-tRNAf into initiation complexes showed that while the level of labeled 40S initiation complex in lysates from treated cells was the same or higher than in control lysates, the rate or efficiency of formation of the 80S initiation complex was inhibited. These results imply that the transcriptional inhibitors do not affect the level or charging of the initiation tRNAMet, the activity of the eIF-2 initiation factor needed for ternary complex formation, and the availability of active 40S ribosomal subunits. Thus, this site of action is different from that observed in other translational control systems such as the hemin response in reticulocytes and the interferon-induced translation inhibition in virally infected cells. This effect may reflect the cell's coordination of nuclear transcription and cytoplasmic translation.

Effect of temperature on protein and immunoglobulin synthesis and secretion in two mouse myeloma cell lines

Protein synthesis in differentiated MOPC-21 and MPC-11 mouse myeloma cells was studied to determine the basis for the differences in the temperature and actinomycin D sensitivity of translation between non-differentiated mouse L-cells and differentiated rabbit reticulocytes. The temperature dependence of total protein synthesis was similar to that of L-cells and reticulocytes, being biphasic in Arrhenius plots with apparent activation energies of approximately 25 and 42 kcal/mol, above and below 25 degress C. The dependence of the secretion process was different since it was not biphasic, having a single activation energy of about 22 kcal/mol. Myeloma polysomes were like L-cell polysomes in their response to lower temperature and reached a minimum level of 50% at 15 degress C. This response was also found for the specific polysomes synthesizing the IgG H- and L-chains. In the presence of actinomycin D, myeloma polysomes declined exponentially with a half-life of approximately 6 hours. These two L-cell-like responses were not found in reticulocytes. Translation of both the IgG mRNAs and the non-IgG mRNAs was reduced by lower temperatures and actinomycin D, even though the L-chain mRNA was slightly more resistant, suggesting that this mRNA is slightly more efficient. The results of these experiments suggest that the translational differences between L-cells and reticulocytes are not mRNA dependent, but are cell type differences.