bluuebunny/crossref_metadata_2025_split huggingface dataset:
The development of a dynamic model to simulate boiler controls
Authors: Damianos XS , Day AR , Ratcliffe MS 
Published: April 2007

There has long been the need to improve the guidance for the control of multiple boiler installations. The literature shows that there is no generic guidance on how boiler plant — as opposed to the heating system — should be best controlled, despite their widespread use and many years of experience with these systems. This paper presents a simulation model that enables detailed investigation of multiple boiler operation under different control regimes. Five different conditions are presented in this paper. The first three show that individual boiler firing patterns behave as would be expected under ideal conditions. The loads for these simulations were chosen specifically to test this, and to provide some verification of the model. Two further tests were conducted to show firing patterns that may occur under typical control regimes. The resulting firing patterns showed unnecessary cycling of both boilers, a cause of premature failure and reduced efficiency. Practical applications: This paper presents the first stages of an investigation into the setting up and operation of multiple boiler control systems. A review of academic and industrial literature shows there to be very little guidance on how such control systems should be configured, and how different configurations will affect the system performance. This work is developing validated boiler models that can be used to investigate how sensor positioning and switching differentials can affect firing rates and interactions between boiler modules. In this way control settings can be more appropriately specified and commissioned. Excessive boiler cycling can lead to early failure of boilers and increased energy use. The results presented in this paper show that interaction between boilers due to poor sequence control settings will lead to additional and unnecessary cycling of boilers under part load conditions. The guidance arising from this work will help to extend boiler life and reduce fuel waste.
Analysis of vertical ground loop heat exchangers applied to buildings in the UK
Authors: Underwood C.P. , Spitler J.D. 
Published: April 2007

The work presented here deals with the design and performance of ground-source heat pumps and ground-sink cooling systems using vertical borehole arrays for commercial applications in the UK. Heating and cooling energy demands for a range of building and HVAC plant options are obtained by thermal modelling applied to four HVAC plant options: space heating only; heating with chilled ceilings; fan coil units and constant volume all-air plant. Ground loop designs are conducted for each system option using an impulse-response method and the parameters extracted from this are used in 10-year simulations of plant response which have been carried out using HVACSIM+. The 10-year time horizon was used to assess any degradation in earth temperature over time. The results show that a substantial reduction in energy (and, hence, carbon) can be expected of up to and exceeding 50% when using ground source heat pumps for winter heating with direct cooling in summer in association with moderate temperature cooling systems such as chilled ceilings. A degradation of earth temperature was evident with systems utilising limited cooling or no cooling but this did not appear to influence heat pump performance greatly. Practical Applications: Design and performance data for use in vertical ground loop (borehole) heat exchanger arrays providing source heat for heat pumps as well as direct cooling for buildings are generated and reported in this paper. The data should be of help to design practitioners for the sizing of borehole arrays for both heating and cooling. Design and performance matching to a wide variety of HVAC combinations, building energy demand levels and two contrasting sets of earth thermal property data are included so that practitioners will be able to select results that suit a range of modern applications. Also included are results of 10-year energy simulations that demonstrate the required design and operating conditions needed to ensure that initial undisturbed earth conditions will not drift with time to an unacceptable extent. Comparisons are made with conventional heating and cooling methods so that estimates of carbon savings due to the use of ground-coupled heat pumps with (and without) direct cooling can be made.
Technical note
Authors: McLean RC , Danert K. , Morrison SJ , Galbraith GH 
Published: April 2007

The major defence available to the body in high-temperature occupational exposures is the evaporation of sweat and the calculation of the evaporation rate forms a central part of the assessment procedure for determining a safe working pattern. This calculation is conventionally carried out on the basis of a steady-state sweat rate, which neglects the gradual onset of sweating at the beginning of an exposure. The maximum exposure period determined on this basis will overestimate the safe working time. This paper presents the background to a correction, which can be applied to such a conventionally-determined maximum exposure period to take account of sweating onset. Practicalapplication: In an occupational hot exposure situation, the assessment of a safe working period is critically dependent on an accurate evaluation of the body energy loss by sweat evaporation. Numerical assessment methods conventionally calculate this component on the assumption of a step change to the steady-state value immediately on commencement of an exposure. As sweating onset is a gradual process, this can lead to a serious overestimation of the accumulated sweat loss and safe exposure period. The outcome of the accompanying paper is a numerical relationship which allows the maximum exposure period calculated on a steady-state basis to be corrected to take account of sweating onset. The form of this correction shows that its application is particularly important in short exposures with a high evaporative loss.
The Epidemiology of Shoulder Injuries in English Professional Rugby Union
Authors: Headey Julia , Brooks John H. M. , Kemp Simon P. T. 
Published: April 2007

Background Shoulder injuries constitute a considerable risk to professional rugby union players; however, there is a shortage of detailed epidemiologic information about injuries in this population. Purpose To describe the incidence, severity, and risk factors associated with shoulder injuries in professional rugby union. Study Design Descriptive epidemiology study. Method Medical personnel prospectively reported time-loss injuries in professional rugby union in England, and the shoulder injuries were evaluated. Results The incidence of shoulder injuries was significantly lower during training (0.10/1000 player—training hours) compared with matches (8.9/1000 player—match hours). The most common match injury was acromioclavicular joint injury (32%); the most severe was shoulder dislocation and instability (mean severity, 81 days absent), which also caused the greatest proportion of absence (42%) and had the highest rate of recurrence (62%). The majority of match shoulder injuries were sustained in the tackle (65%), and outside backs were the most likely to sustain an injury from tackling (2.4/1000 player-tackles). Injuries sustained during training were significantly more severe (61 days) than were those sustained during match play (27 days), and defensive training sessions carried the highest risk of injury (0.45/1000 player-hours; mean severity, 67 days). A mean of 241 player-days per club per season were lost to shoulder injuries. Conclusion Results suggest the potential to reduce this injury burden by modifying training activities and implementing “prehabilitation” strategies in an effort to minimize the risk of shoulder dislocation/instability.
Simultaneously optimizing dose and schedule of a new cytotoxic agent
Authors: Braun Thomas M. , Thall Peter F. , Nguyen Hoang , de Lima Marcos 
Published: April 2007

Background Traditionally, phase I clinical trial designs are based upon one predefined course of treatment while varying among patients the dose given at each administration. In actual medical practice, patients receive a schedule comprised of several courses of treatment, and some patients may receive one or more dose reductions or delays during treatment. Consequently, the overall risk of toxicity for each patient is a function of both actual schedule of treatment and the differing doses used at each adminstration. Purpose Our goal is to provide a practical phase I clinical trial design that more accurately reflects actual medical practice by accounting for both dose per administration and schedule. Methods We propose an outcome-adaptive Bayesian design that simultaneously optimizes both dose and schedule in terms of the overall risk of toxicity, based on time-to-toxicity outcomes. We use computer simulation as a tool to calibrate design parameters. Results We describe a phase I trial in allogeneic bone marrow transplantation that was designed and is currently being conducted using our new method. Our computer simulations demonstrate that our method outperforms any method that searches for an optimal dose but does not allow schedule to vary, both in terms of the probability of identifying optimal (dose, schedule) combinations, and the numbers of patients assigned to those combinations in the trial. Limitations Our design requires greater sample sizes than those seen in traditional phase I studies due to the larger number of treatment combinations examined. Our design also assumes that the effects of multiple administrations are independent of each other and that the hazard of toxicity is the same for all administrations. Conclusions Our design is the first for phase I clinical trials that is sufficiently flexible and practical to truly reflect clinical practice by varying both dose and the timing and number of administrations given to each patient. Clinical Trials 2007; 4: 113—124. http://ctj.sagepub.com
Small-angle neutron scattering investigation of the effect of a heat-treatment on the microstructure of porous basalt rocks
Authors: Kahle A. , Winkler B. , Radulescu A. 
Published: April 2007

AbstractSmall-angle neutron scattering has been used to study the microstructure of natural porous basalt rocks. The effect of temperature on the rock microstructure has been investigated on ‘as received’ and heat-treated basalts. The magnitudes of α, the power-law scattering exponent were between 3 and 4 for the majority of the rocks, indicating a surface fractal structure between the basalt matrix and the pore space. Heat-treated basalts show higher α values, and therefore a smoother pore surface. Internal surface areas were determined for all basalts depending on the thermal history.
Chemical zonation and relative timing of growth sections in garnets from eclogites of the Leaota Massif, South Carpathians
Authors: Săbău G. , Negulescu E. , Massonne H.-J. 
Published: April 2007

AbstractWe have investigated the chemical zoning of garnet in three texturally different eclogite types from the Leaota Massif, Romania, to test the various zonation patterns of Ca, Fe, Mg and Mn as indices of time-lines in porphyroblastic garnets. Mn zonation was found to mark various growth stages very well. It indicates in each of our three case studies a complex growth history dominated by multiple nucleation and coalescence, but also interrupted by partial resorption, as shown by morphological characteristics. Chemical variations of the main elements in garnet during prograde high-pressure metamorphism define time-lines other than those of Mn which decrease, highlighting the stages of porphyroblastic growth. In particular, the Ca/Mn, Mg/Mn and Mg/Fe ratios are useful in late growth stages, when low Mn contents and radial gradients do not allow a satisfactory resolution of Mn time-lines. These ratio-based time-lines further substantiate the potential of Mn time-lines in revealing non-concentric porphyroblastic growth. This is important in order to correctly relate garnet growth stages to stable mineral assemblages, a prerequisite for a reliable derivation of the metamorphic history of the host rock.
Origin of the secondary REE-minerals at the Paratoo copper deposit near Yunta, South Australia
Authors: Brugger J. , Ogierman J. , Pring A. , Waldron H. , Kolitsch U. 
Published: April 2007

AbstractThe Paratoo copper deposit, located in the Neoproterozoic to Cambrian Adelaide Geosyncline, South Australia, produced around 360 tons of Cu between 1888 and 1967 from oxidized ores. The deposit is located in the core of a breached, doubly plunging anticline, near a zone of disruption containing brecciated Adelaidean sedimentary rocks and dolerite (‘Paratoo Diapir’), and hosted in dolomitic shales of the Neoproterozoic Burra Formation. Near the surface, the mineralization resides mainly in deeply weathered quartz-magnetite-sulphide (pyrite, chalcopyrite) veins (⩽10 cm wide). At depth, drill cores reveal disseminated magnetite, pyrite, chalcopyrite, copper sulphide and native copper associated with extensive potassic alteration. K-Na-rich fluids also affected the dolerite in the ‘Paratoo diapir’, resulting in the precipitation of K-feldspar, dravite and K-bearing chabazite-Na. The most likely scenario for the genesis of the Paratoo deposit involves circulation of basinal fluids, focusing into the ‘Paratoo Diapir’, and ore precipitation through neutralization by fluid-rock interaction with the dolomitic shales hosting the mineralization.The Paratoo deposit is deeply weathered, with malachite and chrysocolla (± tenorite and cuprite) containing the bulk of the copper recovered from the shallow workings. A diverse assemblage of secondary REE-bearing carbonate minerals, including the new species decrespignyite-(Y) and paratooite-(La), is associated with the weathered base metal and magnetite ores. Whole-rock geochemical analyses of fresh and mineralized host rock and of vein material reveals that the mineralization is associated with a strong, albeit highly variable, enrichment in light rare earth elements (LREE). This association indicates that REE and base metals were introduced by the same hydrothermal fluid. The strong negative Ce anomaly found in secondary REE minerals and mineralized rock samples suggests an upgrade of the REE contents in the weathering zone, insoluble Ce4+ being left behind.The Fe-oxide-REE-base metal association at Paratoo is also characteristic of the giant Mesoproterozoic Fe oxide copper gold deposit of Olympic Dam, located 350 km to the NW. A similar association is found in the Palaeozoic deposits of the Mt Painter Inlier, 300 km to the NNE. The widespread occurrence of this elemental association in the Province probably reflects the geochemistry of the basement, which contains numerous Mesoproterozoic granites enriched in REE and U.
A survey of accessory mineral assemblages in peralkaline and more aluminous A-type granites of the southeast coastal area of China
Authors: Xie L. , Wang R. C. , Wang D. Z. , Qiu J. S. 
Published: April 2007

AbstractAn extensive belt of A-type granite exists along the southeast coast of China. The granites are divided into peralkaline and more aluminous subgroups which differ in mineral assemblages, mineral compositions and textures. In the peralkaline subgroup, primary magmatic Th-rich zircon is typically overgrown by Th-poor zircon containing thorite micro-inclusions. REE minerals in this subgroup are dominated by allanite-(Ce), chevkinite-(Ce), titanite and pyrochlore. Fe-Ti oxides are titanian magnetite and Mn-rich ilmenite. In contrast, in the more aluminous subgroup rocks, zircon is weakly zoned and exhibits very low Th but relatively high U contents. The REE minerals are dominated by Th-rich monazite-(Ce). Titanium-poor magnetite, pyrophanite and rutile are the major Fe-Ti oxides. These occurrences indicate that peralkaline magmas favour the formation of REE silicates, whereas magmas with higher alumina saturation stabilize REE phosphates. Peralkaline granites crystallized at temperatures 50–100°C greater than the more aluminous granites, but under lower oxidation conditions. These differences in formation conditions of the two A-type granite subgroups, deduced by accessory mineralcharacteristics, are inferred to be related to magma derivation at different crustal levels, with peralkaline magma deriving from a deeper crustal level with more mantle input.
Interactions between epithelial cells and leukocytes in immunity and tissue homeostasis
Authors: Shaykhiev Renat , Bals Robert 
Published: April 2007

AbstractEpithelial cells (ECs) cover the surfaces of the body such as skin, airways, or the intestinal tract and provide an important link between the outside environment and the body interior. Leukocytes play a critical role in immunity, as they are the predominant cell population involved in inflammation and the only cells providing adaptive immune response to pathogenic microorganisms. ECs and leukocytes form a complex network, which regulates processes such as host defense, immunity, inflammation, tissue repair, and cancer growth. One of the most critical functions of ECs is to keep up a barrier to the outside and to protect the sensitive immune system from continuous contact with external microorganisms. An appropriate response to wounding or danger involves not only killing of microbes but also regulation of tissue repair and reconstitution of the barrier system. Dysregulated response to damage represents a pathophysiological mechanism, which leads to autoimmunity, chronic inflammatory diseases, and cancer development. The networks described here are involved in virtually all diseases that take place at body surfaces. In this article, we develop a concept of epithelial barrier as a critical regulator of leukocyte function and discuss how host defense processes modulate epithelial homeostasis.
Efficacy of Letrozole Extended Adjuvant Therapy According to Estrogen Receptor and Progesterone Receptor Status of the Primary Tumor: National Cancer Institute of Canada Clinical Trials Group MA.17
Authors: Goss Paul E. , Ingle James N. , Martino Silvana , Robert Nicholas J. , Muss Hyman B. , Piccart Martine J. , Castiglione Monica , Tu Dongsheng , Shepherd Lois E. , Pritchard Kathleen I. , Livingston Robert B. , Davidson Nancy E. , Norton Larry , Perez Edith A. , Abrams Jeffrey S. , Cameron David A. , Palmer Michael J. , Pater Joseph L. 
Published: April 2007

Purpose Controversy exists regarding estrogen (ER) and progesterone (PgR) receptor expression on efficacy of adjuvant endocrine therapy. In the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial, the benefit of anastrozole over tamoxifen was substantially greater in ER+/PgR–than ER+/PgR+ tumors. In BIG 1-98 (Breast International Group), the benefits of letrozole over tamoxifen were the same in ER+ tumors irrespective of PgR. MA.17 randomized postmenopausal women after 5 years of tamoxifen, to letrozole or placebo. We present outcomes according to tumor receptor status. Patients and Methods Disease-free survival (DFS) and other outcomes were assessed in subgroups by ER and PgR status using Cox's proportional hazards model, adjusting for nodal status and prior adjuvant chemotherapy. Results The DFS hazard ratio (HR) for letrozole versus placebo in ER+/PgR+ tumors (N = 3,809) was 0.49 (95% CI, 0.36 to 0.67) versus 1.21 (95% CI, 0.63 to 2.34) in ER+/PgR–tumors (n = 636). ER+/PgR+ letrozole patients experienced significant benefit in distant DFS (DDFS; HR = 0.53; 95% CI, 0.35 to 0.80) and overall survival (OS; HR = 0.58; 95% CI, 0.37 to 0.90). A statistically significant difference in treatment effect between ER+/PgR+ and ER+/PgR–subgroups for DFS was observed (P = .02), but not for DDFS (P = .06) or OS (P = .09). Conclusion These results suggest greater benefit for letrozole in DFS, DDFS, and OS in patients with ER+/PgR+ tumors, implying greater activity of letrozole in tumors with a functional ER. However, because this is a subset analysis and receptors were not measured centrally, we caution against using these results for clinical decision making.
Infection Control: A Survey of UK Special Care Dentists and Dental Care Professionals
Authors: Scully Crispian , Moles David R , Fiske Janice 
Published: April 2007

Aim To determine attitudes to and practice of infection control among practitioners involved in special care dentistry. Methods A questionnaire on the issues of decontamination and infection control was sent to all 680 members of the British Society for Disability and Oral Health. Results The response rate was 63.5%. Almost all respondents (95%) reported having a local infection-control policy; most (97%) had local protocols for the management of inoculation injuries; most (81%) gave new staff training in infection-control procedures and most (74%) provided updates for established staff. Most respondents ‘usually’ or ‘always’ provided eye protection for patients (95%) and themselves (93%). Virtually all routinely wore gloves, and nearly all (94%) ‘always’ changed gloves between patients. The majority ‘usually’ or ‘always’ disinfected or disposed of surface coverings between patients (98%), sterilised all non-disposable instruments that had been set out for the patient (99%), and disinfected laboratory work (96%). Conclusions There was high awareness of infection-control issues, and good reported compliance among these dental workers.
Inactivation of Pten in Osteo-Chondroprogenitor Cells Leads to Epiphyseal Growth Plate Abnormalities and Skeletal Overgrowth
Authors: Ford-Hutchinson Alice Fiona , Ali Zenobia , Lines Suzen Elizabeth , Hallgrímsson Benedikt , Boyd Steven Kyle , Jirik Frank Robert 
Published: April 2007

Abstract
To study the role of the Pten tumor suppressor in skeletogenesis, we generated mice lacking this key phosphatidylinositol 3′-kinase pathway regulator in their osteo-chondroprogenitors. A phenotype of growth plate dysfunction and skeletal overgrowth was observed.
Introduction: Skeletogenesis is a complex process relying on a variety of ligands that activate a range of intracellular signal transduction pathways. Although many of these stimuli are known to activate phosphatidylinositol 3′-kinase (PI3K), the function of this pathway during cartilage development remains nebulous. To study the role of PI3K during skeletogenesis, we used mice deficient in a negative regulator of PI3K signaling, the tumor suppressor, Pten.
Materials and Methods: Pten gene deletion in osteo-chondrodroprogenitors was obtained by interbreeding mice with loxP-flanked Pten exons with mice expressing the Cre recombinase under the control of the type II collagen gene promoter (Ptenflox/flox:Col2a1Cre mice). Phenotypic analyses included microcomputed tomography and immunohistochemistry techniques.
Results: μCT revealed that Ptenflox/flox:Col2a1Cre mice exhibited both increased skeletal size, particularly of vertebrae, and massive trabeculation accompanied by increased cortical thickness. Primary spongiosa development and perichondrial bone collar formation were prominent in Ptenflox/flox:Col2a1Cre mice, and long bone growth plates were disorganized and showed both matrix overproduction and evidence of accelerated hypertrophic differentiation (indicated by an altered pattern of type X collagen and alkaline phosphatase expression). Consistent with increased PI3K signaling, Pten-deficient chondrocytes showed increased phospho-PKB/Akt and phospho-S6 immunostaining, reflective of increased mTOR and PDK1 activity. Interestingly, no significant change in growth plate proliferation was seen in Pten-deficient mice, and growth plate fusion was found at 6 months.
Conclusions: By virtue of its ability to modulate a key signal transduction pathway responsible for integrating multiple stimuli, Pten represents an important regulator of both skeletal size and bone architecture.