125 research outputs found
Monitoring and Performance Analysis of a Large Non-domestic Ground Source Heat Pump Installation
Application of GSHP systems to provide heating and cooling for non-domestic buildings is seen as a viable and effective way of reducing carbon emissions and achieving design renewable energy targets. The application of GSHP systems and their optimal design can be improved through use of reliable system design and simulation models. To assess the validity of design models, availability of high quality field data is critical. Many experimental and monitoring studies have been concerned with domestic scale GSHP installations. In this research work a monitoring system has been implemented to collect high quality dataset from functioning GSHP heating and cooling system in a large educational building at De Montfort University. Operational data have been logged for every minute since the system was commissioned and will provide high quality heat transfer and energy data that will be used for GSHP system model development and validation. Preliminary performance analysis has been carried out and this paper describes the GSHP installation and the monitoring system. Operational data collected over the first year is presented along with a detailed analysis of system performance. The daily average COP of Heat Pumps varied between 3 and 6. The seasonal COP of the system was found to be 4.13. When the ground loop circulating pump was taken into consideration the seasonal COP was found to be 3.41. The reasons for performance variation over different periods are discussed
Avascular necrosis of bone following renal transplantation
This study was undertaken to determine the incidence and clinical features of avascular necrosis of bone in 69 transplant recipients all of whom had a functioning allograft for a least 12 months. An attempt was also made to identify any potential predisposing factors. The patients were assessed by an orthopaedic surgeon. The diagnosis of avascular necrosis was tnade on the basis of radiographs and isotope bone scans. Fourteen patients (20,2%) developed avascular necrosis with a mean onset of 19 months post-transplantation.The hip joint was most commonly affected. The isotope bone scan was the most sensitive diagnostic tool; abnonnalities were detected before the onset of symptoms in 4 patients. Avascular necrosis was more common in Indian transplant recipients and was also associated with: (i) cadaver transplants; (ii) more frequent bouts of acute rejection (P < 0,05); and (iii) a greater incidence of other steroid-associated side-effects (P < 0,05).Alcohol conswnption and radiological evidence of osteoporosis were more prevalent in the avascular necrosis group (42,8% v. 29,0% and 28,5% v. 7,2% respectively). Avascular necrosis did not correlate with age, sex, renal function at 1 year or severe secondary hyperparathyroidism.This study suggests that corticosteroid therapy plays an important role in the pathogenesis of avascular necrosis. Excessive alcohol conswnption and osteoporosis also appear to be risk factors
Attitude to the study of chemistry and its relationship with achievement in an introductory undergraduate course
A positive attitude to a subject may be congruent with higher achievement; however, limited evidence supports this for students in undergraduate chemistry – this may result from difficulties in quantifying attitude. Therefore, in this study, the Attitude to the Study of Chemistry Inventory (ASCI) – a validated instrument to quantify attitude, was used to measure attitude to chemistry in 125 undergraduates s udying an introductory course in chemistry, as part of a BSc Chemistry major. The 13 week course contained 4 summative assessments: practical (PRAC), tutorial (TUT), on-line web-based learning (OWL), and a final exam (FE). Sub-scales within ASCI which quantify the
‘affective’ and ‘cognitive’ components of attitude were determined. Firstly, for all 125 students, weak correlations (r) between the affective scale score and FE
(r=0.275, P<0.01) and TOTAL (r=0.228, P<0.05), were recorded. Secondly, a low achieving (LA, n=48) and a high achieving (HA, n=77) group were identified using a cluster analysis procedure. The HA group scored higher than the LA
group in PRAC, OWL, FE and TOTAL (all P<0.001), but the clusters were not different in their scores for either the affective or the cognitive components of attitude. There was no correlation between attitude and achievement in the HA group, and only one weak positive correlation (0.409), between the affective score and achievement in the LA group. We suggest that although a positive attitude may be an important part of the undergraduate experience, it is at best only weakly associated with achievement in undergraduate chemistry
Annual ryegrass (Lolium rigidum Gaud) competition altered wheat grain quality: a study under elevated atmospheric CO2 levels and drought conditions
Annual ryegrass is one of the most serious, costly weeds of winter cropping systems in Australia. To determine whether its competition-mediated plant defence mechanisms effect on wheat grain quality, wheat (cv. Yitpi) and annual ryegrass were grown under two levels of CO (400 ppm; (a[CO]) vs 700 ppm; (e[CO]), two levels of water (well-watered vs drought) and two types of competition (wheat only; (W), and wheat × annual ryegrass; (W × R) with four replicates. The competition × [CO] interaction had a significant effect on wheat grain protein content, where it was increased in W × R under both e[CO] (+17%) and a[CO] (+21%). Grain yield, total grain reducing power and phenolic content were significantly affected by [CO] × drought × competition. In a summary, annual ryegrass competition significantly altered the wheat grain quality under both [CO] levels (depending on the soil water level), while also decreasing the grain yield
Challenges and opportunities in the design and construction of a GIS-based emission inventory infrastructure for the Niger Delta region of Nigeria
© 2017, Springer-Verlag Berlin Heidelberg. Environmental monitoring in middle- and low-income countries is hampered by many factors which include enactment and enforcement of legislations; deficiencies in environmental data reporting and documentation; inconsistent, incomplete and unverifiable data; a lack of access to data; and technical expertise. This paper describes the processes undertaken and the major challenges encountered in the construction of the first Niger Delta Emission Inventory (NDEI) for criteria air pollutants and CO2 released from the anthropogenic activities in the region. This study focused on using publicly available government and research data. The NDEI has been designed to provide a Geographic Information System-based component of an air quality and carbon management framework. The NDEI infrastructure was designed and constructed at 1-, 10- and 20-km grid resolutions for point, line and area sources using industry standard processes and emission factors derived from activities similar to those in the Niger Delta. Due to inadequate, incomplete, potentially inaccurate and unavailable data, the infrastructure was populated with data based on a series of best possible assumptions for key emission sources. This produces outputs with variable levels of certainty, which also highlights the critical challenges in the estimation of emissions from a developing country. However, the infrastructure is functional and has the ability to produce spatially resolved emission estimates
Bringing Darkness to Light: The Influence of Auditor Quality and Audit Committee Expertise on the Timeliness of Financial Statement Restatement Disclosures
This study investigates whether auditor quality and audit committee expertise are associated with improved financial reporting timeliness as measured by the duration of a financial statement restatement’s ‘‘dark period.’’ The restatement dark period represents the length of time between a company’s discovery that it will need to restate financial data and the subsequent disclosure of the restatement’s effect on earnings. For a sample of dark restatements disclosed between 2004 and 2009, we find that companies that engage Big 4 auditors have shorter dark periods than companies that do not engage Big 4 auditors. We also find that companies with more financial experts on the audit committee have shorter dark periods, but only when such financial expertise relates specifically to accounting. Finally, companies with audit committee chairs that have accounting financial expertise provide the most timely disclosures, as the dark periods for these firms are reduced by approximately 38 percent. Our results suggest that both auditor and audit committee expertise are associated with the timely disclosure of restatement details
Characterising neutrophil subtypes in cancer using scRNA sequencing demonstrates the importance of IL-1β/CXCR2 axis in generation of metastasis specific neutrophils
Neutrophils are a highly heterogeneous cellular population. However, a thorough examination of the different transcriptional neutrophil states between health and malignancy has not been performed. We utilized single-cell RNA sequencing of human and murine datasets, both publicly available and independently generated, to identify neutrophil transcriptomic subtypes and developmental lineages in health and malignancy. Datasets of lung, breast, and colorectal cancer were integrated to establish and validate neutrophil gene signatures. Pseudotime analysis was used to identify genes driving neutrophil development from health to cancer. Finally, ligand–receptor interactions and signaling pathways between neutrophils and other immune cell populations in primary colorectal cancer and metastatic colorectal cancer were investigated. We define two main neutrophil subtypes in primary tumors: an activated subtype sharing the transcriptomic signatures of healthy neutrophils; and a tumor-specific subtype. This signature is conserved in murine and human cancer, across different tumor types. In colorectal cancer metastases, neutrophils are more heterogeneous, exhibiting additional transcriptomic subtypes. Pseudotime analysis implicates IL1β/CXCL8/CXCR2 axis in the progression of neutrophils from health to cancer and metastasis, with effects on T-cell effector function. Functional analysis of neutrophil-tumoroid cocultures and T-cell proliferation assays using orthotopic metastatic mouse models lacking Cxcr2 in neutrophils support our transcriptional analysis. We propose that the emergence of metastatic-specific neutrophil subtypes is driven by the IL1β/CXCL8/CXCR2 axis, with the evolution of different transcriptomic signals that impair T-cell function at the metastatic site. Thus, a better understanding of neutrophil transcriptomic programming could optimize immunotherapeutic interventions into early and late interventions, targeting different neutrophil states
An autologous dendritic cell vaccine polarizes a Th-1 response which is tumoricidal to patient-derived breast cancer cells.
Breast cancer remains one of the leading causes of cancer-associated death worldwide. Conventional treatment is associated with substantial toxicity and suboptimal efficacy. We, therefore, developed and evaluated the in vitro efficacy of an autologous dendritic cell (DC) vaccine to treat breast cancer. We recruited 12 female patients with stage 1, 2, or 3 breast cancer and matured their DCs with autologous tumour-specific lysate, a toll-like receptor (TLR)-3 and 7/8 agonist, and an interferon-containing cocktail. The efficacy of the vaccine was evaluated by its ability to elicit a cytotoxic T-lymphocyte response to autologous breast cancer cells in vitro. Matured DCs (≥ 60% upregulation of CD80, CD86, CD83, and CCR7) produced high levels of the Th1 effector cytokine, IL12-p70 (1.2 ng/ml; p < 0.0001), compared to DCs pulsed with tumour lysate, or matured with an interferon-containing cocktail alone. We further showed that matured DCs enhance antigen-specific CD8 + T-cell responses to HER-2 (4.5%; p < 0.005) and MUC-1 (19%; p < 0.05) tetramers. The mature DCs could elicit a robust and dose-dependent antigen-specific cytotoxic T-lymphocyte response (65%) which was tumoricidal to autologous breast cancer cells in vitro compared to T-lymphocytes that were primed with autologous lysate loaded-DCs (p < 0.005). Lastly, we showed that the mature DCs post-cryopreservation maintained high viability, maintained their mature phenotype, and remained free of endotoxins or mycoplasma. We have developed a DC vaccine that is cytotoxic to autologous breast cancer cells in vitro. The tools and technology generated here will now be applied to a phase I/IIa clinical trial
Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries
Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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