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The year 2000 radiative forcing (RF) due to changes in O3 and CH4 (and the CH4-induced stratospheric water vapour) as a result of emissions of short-lived gases (oxides of nitrogen (NOx), carbon monoxide and non-methane hydrocarbons) from three transport sectors (ROAD, maritime SHIPping and AIRcraft) are calculated using results from five global atmospheric chemistry models. Using results from these models plus other published data, we quantify the uncertainties. The RF due to short-term O3 changes (i.e. as an immediate response to the emissions without allowing for the long-term CH4 changes) is positive and highest for ROAD transport (31 mW m−2) compared to SHIP (24 mW m−2) and AIR (17 mW m−2) sectors in four of the models. All five models calculate negative RF from the CH4 perturbations, with a larger impact from the SHIP sector than for ROAD and AIR. The net RF of O3 and CH4 combined (i.e. including the impact of CH4 on ozone and stratospheric water vapour) is positive for ROAD (+16(±13) (one standard deviation) mW m−2) and AIR (+6(±5) mW m−2) traffic sectors and is negative for SHIP (−18(±10) mW m−2) sector in all five models. Global Warming Potentials (GWP) and Global Temperature change Potentials (GTP) are presented for AIR NOxemissions; there is a wide spread in the results from the 5 chemistry models, and it is shown that differences in the methane response relative to the O3 response drive much of the spread.

BACKGROUND/OBJECTIVES: Whether fat-free mass (FFM) and its components are depleted in eating-disorder (ED) patients is uncertain. Dual energy X-ray absorptiometry (DXA) is widely used to assess body composition in pediatric ED patients; however, its accuracy in underweight populations remains unknown. We aimed (1) to assess body composition of young females with ED involving substantial weight loss, relative to healthy controls using the four-component (4C) model, and (2) to explore the validity of DXA body composition assessment in ED patients. SUBJECTS/METHODS: Body composition of 13 females with ED and 117 controls, aged 10-18 years, was investigated using the 4C model. Accuracy of DXA for estimation of FFM and fat mass (FM) was tested using the approach of Bland and Altman. RESULTS: Adjusting for age, height and pubertal stage, ED patients had significantly lower whole-body FM, FFM, protein mass (PM) and mineral mass (MM) compared with controls. Trunk and limb FM and limb lean soft tissue were significantly lower in ED patients. However, no significant difference in the hydration of FFM was detected. Compared with the 4C model, DXA overestimated FM by 5 ± 36% and underestimated FFM by 1 ± 9% in ED patients. CONCLUSION: Our study confirms that ED patients are depleted not only in FM but also in FFM, PM and MM. DXA has limitations for estimating body composition in individual young female ED patients. European Journal of Clinical Nutrition (2015) 69, 1330-1335; doi: 10.1038/ejcn.2015.111; published online 15 July 2015, INTRODUCTION Eating disorders (ED) involving severe weight loss have a lifetime prevalence in women of 2%-4% in Western industrialized populations, with adolescents most at risk. (1) Patients with anorexia nervosa [...]

BACKGROUND/OBJECTIVES: Bioelectrical impedance analysis (BIA) is widely used to predict body composition in paediatric research and clinical practice. Many equations have been published, but provide inconsistent predictions. AIMS: To test whether a single equation for lean mass (LM) estimation from BIA is appropriate across wide ranges of age, pubertal status and nutritional status, by testing whether specific groups differ in the slope or intercept of the equation. SUBJECTS/METHODS: In 547 healthy individuals aged 4-24 years (240 males), we collected data on body mass (BM) and height (HT), and lean mass (LM) using the 4-component model. Impedance (Z) was measured using TANITA BC418MA instrumentation. LM was regressed on [HT.sup.2]/Z. Multiple regression analysis was conducted to investigate whether groups based on gender, age, pubertal status or nutritional status differed in the association of LM with [HT.sup.2]/Z. RESULTS: BM ranged from 5 to 128 kg. [HT.sup.2]/Z was a strong predictor of LM ([r.sup.2] = 0.953, s.e.e. = 2.9 kg). There was little evidence of a sex difference in this relationship, however, children aged 4-7 years and 16-19 years differed significantly from other age groups in regression slopes and intercepts. Similar variability was encountered for pubertal stage, but not for nutritional status. CONCLUSIONS: No single BIA equation applies across the age range 4-24 years. At certain ages or pubertal stages, the slope and intercept of the equation relating LM to [HT.sup.2]/Z alters. Failure to address such age effects is likely to result in poor accuracy of BIA (errors of several kg) for longitudinal studies of change in body composition. European Journal of Clinical Nutrition (2013) 67, S34-S39; doi: 10.1038/ejcn.2011.213; published online 18 January 2012 Keywords: body composition; bioelectrical impedance analysis; lean mass; total body water; fat-free mass, INTRODUCTION Accurate assessment of body composition in children and adolescents is necessary to discern the effects of diverse diseases, monitor the success of treatment, and guide nutritional or pharmaceutical management. [...]

Background/Objectives: Body composition techniques are required for monitoring response to treatment in individual obese children, and assessing the efficacy of weight loss programmes. Densitometry is readily undertaken, using air displacement plethysmography (ADP), but requires appropriate information on the density of lean tissue ([D.sub.LT]). The aims of this study were to develop predictive equations for [D.sub.LT] in obese children and adolescents, and to test the accuracy of ADP when using such predicted [D.sub.LT] values in an independent longitudinal sample using the four-component model as the reference method. Subjects/Methods: Equations for the prediction of [D.sub.LT] from age, gender and body mass index standard deviation score were developed in 105 children (39 boys). Accuracy of ADP, when incorporating predicted [D.sub.LT] values, was tested for baseline body composition and its change over time in a separate sample of 51 children (20 boys). Results: The predictive equation explained 33% of the variance in [D.sub.LT]. Fat mass obtained from ADP using such predicted values had a mean (s.d.) bias of 0.32 (1.39) kg, nonsignificant, whereas change in fat mass had an error of -0.25 (1.38) kg, nonsignificant. Hydration was strongly correlated with [D.sub.LT]. Conclusions: Use of ADP with predicted [D.sub.LT] values was associated with nonsignificant bias when estimating fat mass and its change over time. This study aids the application of ADP in childhood obesity research and clinical practise. The limits of agreement (± 2.8 kg) relative to four-component values are moderately better than those for X-ray absorptiometry (± 3.2 kg). Further improvement to accuracy would require assessment of lean tissue hydration by bioelectrical impedance. European journal of Clinical Nutrition (2011) 65, 1094-1101; doi: 10.1038/ejcn.2011.76; published online 25 May 2011 Keywords: body composition; densitometry; fat mass; air displacement plethysmography; childhood obesity, Introduction There is growing interest in the measurement of body composition in obese children and adolescents (Wells and Fewtrell, 2008). In clinical practise, body composition assessment may aid assess excess [...]

Previously published work has described the development of a hospital capacity simulation tool, PROMPT. PROMPT has now been adopted by a number of hospitals in the UK and is used for both strategic and operational planning and management of key hospital resources. The work, as presented here, extends the PROMPT functionality to consider in more detail workforce issues. In particular, working with some of the current hospital users, the research has focussed on detailed planning for calculating the size and skill-mix of inpatient nursing teams. The chosen methodology utilizes both simulation and optimization. Outputs from the PROMPT three-phase discrete event simulation are fed into a stochastic programme which suggests the optimal number of nurses to employ (whole time equivalents) by skill-mix and the corresponding numbers by shift. A novel feature of the tool is the ability to predict and compare nursing needs based on different methods of capturing patient-to-nurse ratios as currently adopted across the UK National Health Service. Illustrative results from one hospital demonstrate that although the overall sizes of nursing teams on different wards are of an acceptable level and comparable to the outputs from the simulation phase of the work, often the number of nurses employed at different grades is not well matched to patient needs and the skill-mix should be reconsidered. Results from the optimization phase of the work suggest that it is cost beneficial to increase the number of permanently employed nurses to account for fluctuations in demand and corresponding high costs of temporary (agency) nurses. The scenario functionality of the tool permits for the study of changing size and skill-mix as a consequence of changes in patient volumes, patient case-mix, numbers of beds and length of stay. Journal of the Operational Research Society (2010) 61, 768- 779. doi: 10.1057/jors.2009.43 Published online 13 May 2009 Keywords: simulation; stochastic programming; healthcare modelling; nurse skill-mix

This paper considers the Erlang queueing system M/[E.sub.k]/1, where customers arrive at random at mean rate λ and the service times have an Erlang distribution with parameter k and mean […]

Advances in recent treatments for HIV/AIDS patients have shown dramatic outcomes in extending the incubation period and AIDS survival time, while also providing significant improvements in the quality of patients' lives. A compartmental model is proposed to analyse the effects of the various treatment regimens which have been introduced. The results produced are in good agreement with routinely collected data relating to levels of HIV/AIDS incidence and prevalence in the UK homosexual population. Some parameter values within the model are obtained from surveys, census results, etc, but others are derived using a maximum likelihood estimation procedure. Finally, the model is used to project levels of incidence and prevalence over the next few years, and to investigate several possible scenarios. Journal of the Operational Research Society (2006) 57, 1413-1424. doi:10.1057/palgrave.jors.2602120 Keywords: HIV/AIDS; compartmental model; treatment effects; maximum likelihood

The intensive care unit (ICU) of a hospital is an essential yet costly resource. Consequently, intensive care modelling has become increasingly prevalent in recent years in attempts to increase efficiency and reduce costs. Previous models have usually assumed that the numbers of beds available are restricted; when all beds are occupied, any additional patients are referred elsewhere or elective surgeries are cancelled. In this study, activities at the ICU at a large teaching hospital were modelled using data relating to all admissions to the ICU during the year 2000--a total of 1084 admissions. The unit is unusual in that the majority of patients referred for intensive care therapy are admitted. Bed numbers are increased when necessary to cope with demand. However, nurses are a restricted resource. In order to maintain the required nurse:patient ratio of at least one:one, supplementary nurses are employed during busy periods. Supplementary nurse costs are substantial and so nurse utilization must be closely monitored. The development of a model that calculates the required number of supplementary nurses per shift, and also encapsulates the time-dependent nature of elective surgery admissions and complex duration-of-stay profiles, is presented in this paper. In particular, the model is used to determine the number of rostered nurses that are required to minimize overall nursing staff costs. Keywords: simulation; health; hospitals

Condensed tannins in forage legumes can be beneficial or detrimental to ruminant livestock performance, depending on concentration. The objective of this research was to determine condensed tannin concentration in birdsfoot trefoil (Lotus comiculatus L.) without rhizomes (BFT) and with rhizomes (RBFT) from grazed monocultures and mixtures. An additional objective was to investigate possible fluctuation of condensed tannin concentrations through the spring grazing season. In 1997, `Norcen' BFT and `ARS-2620' RBFT were sown into pastures located at Columbia, MO; pastures were pure stands or mixtures with tall fescue (TF; Festuca arundinacea Schreb). Pastures were grazed in 1998 and 1999, and the BFT and RBFT components were hand clipped every 14 d throughout the spring of 1998 and 1999. Samples were analyzed for condensed tannin concentration by near infrared (NIR) reflectance spectroscopy with calibrations based on the vanillin--HCl colorimetric method. Condensed tannin concentrations of grazed BFT were lower in this study than concentrations reported in other studies. Averaged over both years, BFT contained 11.4 g catechin equivalents (CE) [kg.sup.-1] DM, and RBFT contained (P < 0.05) three times that amount (38.6 g CE [kg.sup.-1] DM). Also, condensed tannin concentrations of the BFT component were 100% higher when BFT was grown in a mixture instead of a pure stand (P < 0.10); in 1999, they were 55% higher (P < 0.05). Finally, condensed tannin concentration fluctuated over the spring of 1998 (P < 0.05), but not the spring of 1999. We concluded that condensed tannins in BFT are much lower than in RBFT, that condensed tannins in BFT decrease when grown with a tail fescue companion grass, and that concentrations can fluctuate in the spring as they do in the autumn., TANNINS ARE POLYPHENOLIC NATURAL PRODUCTS that can precipitate proteins (Reed, 1995). Hydrolyzable tannins have small molecular weights and include simple phenolic acids and glucose. Condensed tannins are large oligomeric proanthocyanidins [...]

This study investigated the performance of steers grazing rhizomatous birdsfoot trefoil (Lotus corniculatus L.) (RBFT) compared to nonrhizomatous birdsfoot trefoil (BFT) in pure stands or when interseeded with endophyte-free tall fescue (Festuca arundinacea Schreb.; TF). Five forage treatments of RBFT, BFT, TF, RBFT+TF, and BFT+TF (four replicate paddocks per treatment) were continuously stocked in spring and fall of 1998 and spring of 1999. Grazing for individual treatments was terminated when pasture mass fell below 900 kg/ha. Average daily gain was greatest (P < 0.10) in pure stands of BFT and RBFT, but total forage production, and thus grazing days, for these treatments was low. Average daily gain for steers grazing BFT+TF and RBFT+TF treatments was not different from (spring and fall 1998) or greater (P < 0.10) (spring 1999) than that for TF. Total forage production of BFT+TF and RBFT+TF was greater (P < 0.10) than that of TF in spring 1998. In fall 1998, BFT+TF produced more (P < 0.10) total forage than either RBFT+TF or TF, and in spring 1999, RBFT+TF had less (P < 0.10) total forage than TF or BFT+TF. Total steer days on mixed pastures were greater (P < 0.10) than that for TF in spring and fall 1998 but not different from those for TF in spring 1999. In all three trials total weight gain/hectare was greater (P < 0.10) for RBFT+TF and BFT+TF than for TF. The RBFT+TF and BFT +TF had greater (P < 0.05) CP than TF in spring and fall 1998 and less (P < 0.05) NDF and ADF in fall 1998. We concluded that either RBFT or BFT could be interseeded with tall fescue to enhance ADG and total steer days. Key Words: Festuca arundinacea, Forage, Lotus corniculatus, Performance, Quality, Steers