• Rediscovering and conserving the Lower Palaeozoic 'treasures' of Ethel Woods (nee Skeat) and Margaret Crosfield in northeast Wales

      Burek, Cynthia V.; Malpas, Jacqui A.; University of Chester ; NEWRIGS, Millenium EcoCentre in Wrexham (2007)
      This book chapter explores, within a historical context, the importance of geoconservation of not only sitesbut also artefacts, collections and specimens as well as letters and original documents. It sets but the search and finding of sites in northeast Wales and materials thought lost then found and the subsequent nomination of Regionally Important Geological/Geomorphological Sites (RIGS) conservation status of the sites to safeguard them for the future. It is important to note that RIGS can be designated for their historical value alone, which is in contrast to Sites of Special Scientific Inleresi (SSSIs), which are protected solely for their national scientific and research value. The role of Ethel Woods (nee Skeat) and Margaret Crosfield in developing an understanding of the geological history of northeast Wales had been lost over time. This paper contains biographical sketches of the two women, followed by their Lower Palaeozoic lithological, structural and grap-tolite research and places it in an historical context. This case study illustrates how female curiosity, perseverance and attention to detail unearthed previously forgotten treasures. The importance of conserving their sites, specimens and sketch field notebooks in our electronic and throw-away age is vital. The role of the North East Wales Regionally Important Geological/ Geomorphological Sites (NEWRIGS) in conserving this information is put forward as an example of good practice.
    • Reduction in high intensity activity during senior elite rugby league matches

      Sykes, Dave; Twist, Craig; Lamb, Kevin L.; Nicholas, Ceri; University of Chester (2009-06)
    • A reflective account of a consultation in abortion care

      Astbury-Ward, Edna; Western Cheshire PCT (Scutari Projects, 2009)
      This article presents a reflective account of a consultation in a pre-assessment clinic for women requesting abortion. The reflection is based on Johns' model. Reflection enabled the author to address important issues that the consultation raised. These included the realisation that nurses do not always have to understand why patients make the choices they do, and the importance of allocating sufficient time for sensitive consultations.
    • Regional differences in mechanical and material properties of femoral head cancellous bone in health and osteoarthritis

      Brown, Sharon J.; Pollintine, Phillip; Powell, Diane E.; Davie, Michael W. J.; Sharp, Christopher A.; Charles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry/Chester College of Higher Education ; Charles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry ; Charles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry ; Charles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry ; Charles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry (Springer, 2002)
      Osteoarthritis (OA) is a debilitating condition common among the aging population. In this study we have determined mechanical and material properties of cancellous bone cores from two differently loaded regions of femoral heads obtained from healthy subjects and those with end-stage osteoarthritis. Densitometric properties were determined prior to compression testing for Young's modulus (EC) and yield strength (sy), after which bones were powdered for analysis of collagen and mineral content. In both OA and normal cancellous bone, volumetric bone mineral density (BMDv), apparent density (rA), EC, and sy were systematically greater in the superior than in the inferior region (P<0.05). In the OA inferior region, median BMDv (0.434 g-cm-3) and rA (0.426 g-cm-3) were significantly greater than in normals (0.329 and 0.287 g-cm-3, respectively, both P<0.05) reflecting an increased amount of tissue. The mineral:collagen ratio was decreased in OA, but this was only significant in the superior region (P<0.008). Relationships between EC and both BMDv and rA were weaker in OA bone cores (r2 = 0.66 and r2 = 0.59) than in normals (r2 = 0.86 and r2 = 0.77, respectively). Likewise, sy and both BMDv and rA were weaker in OA (r2 = 0.74 and r2 = 0.70) than in normals (r2 = 0.83 and r2 = 0.77, respectively). For the same value of density measure, EC and sy tended to be lower in OA bone when compared with normal bone. In conclusion, femoral head cancellous bone mass in end-stage osteoarthritis is increased but undermineralized, and is neither stiffer nor stronger than normal cancellous bone.
    • Regulation and roles of Ca2+ stores in human sperm.

      Correia, Joao; Michelangeli, Francesco; Publicover, Stephen; University of Birmingham (Bioscientifica, 2015-05-11)
      [Ca(2)(+)]i signalling is a key regulatory mechanism in sperm function. In mammalian sperm the Ca(2)(+)-permeable plasma membrane ion channel CatSper is central to [Ca(2)(+)]i signalling, but there is good evidence that Ca(2)(+) stored in intracellular organelles is also functionally important. Here we briefly review the current understanding of the diversity of Ca(2)(+) stores and the mechanisms for the regulation of their activity. We then consider the evidence for the involvement of these stores in [Ca(2)(+)]i signalling in mammalian (primarily human) sperm, the agonists that may activate these stores and their role in control of sperm function. Finally we consider the evidence that membrane Ca(2)(+) channels and stored Ca(2)(+) may play discrete roles in the regulation of sperm activities and propose a mechanism by which these different components of the sperm Ca(2)(+)-signalling apparatus may interact to generate complex and spatially diverse [Ca(2)(+)]i signals.
    • Regulation of apoptosis by long non-coding RNA GAS5 in breast cancer cells: implications for chemotherapy.

      Pickard, Mark R.; Williams, Gwyn T.; Keele University, United Kingdom (2014-05-01)
      The putative tumour suppressor and apoptosis-promoting gene, growth arrest-specific 5 (GAS5), encodes long ncRNA (lncRNA) and snoRNAs. Its expression is down-regulated in breast cancer, which adversely impacts patient prognosis. In this preclinical study, the consequences of decreased GAS5 expression for breast cancer cell survival following treatment with chemotherapeutic agents are addressed. In addition, functional responses of triple-negative breast cancer cells to GAS5 lncRNA are examined, and mTOR inhibition as a strategy to enhance cellular GAS5 levels is investigated. Breast cancer cell lines were transfected with either siRNA to GAS5 or with a plasmid encoding GAS5 lncRNA and the effects on breast cancer cell survival were determined. Cellular responses to mTOR inhibitors were evaluated by assaying culture growth and GAS5 transcript levels. GAS5 silencing attenuated cell responses to apoptotic stimuli, including classical chemotherapeutic agents; the extent of cell death was directly proportional to cellular GAS5 levels. Imatinib action in contrast, was independent of GAS5. GAS5 lncRNA promoted the apoptosis of triple-negative and oestrogen receptor-positive cells but only dual PI3K/mTOR inhibition was able to enhance GAS5 levels in all cell types. Reduced GAS5 expression attenuates apoptosis induction by classical chemotherapeutic agents in breast cancer cells, providing an explanation for the relationship between GAS5 expression and breast cancer patient prognosis. Clinically, this relationship may be circumvented by the use of GAS5-independent drugs such as imatinib, or by restoration of GAS5 expression. The latter may be achieved by the use of a dual PI3K/mTOR inhibitor, to improve apoptotic responses to conventional chemotherapies.
    • Regulation of Inducible Nitric Oxide Synthase by Arabinoxylans with molecular characterization from Wheat Flour in Cultured Human Monocytes

      Zhengxiao, Zhang; Christopher, Smith; Jason, Ashworth; Weili, Li; Manchester Metropolitan University; University of Chester (Wiley, 2018-01-08)
      The immunomodulatory activity of the arabinoxylans (AXs) extracts from cereal sources has been reported to impart health benefits in terms of immune enhancement. This study investigated the effect of enzymatic extraction on extraction yield and structure of AXs from wheat flour pentosan fraction. Under the optimised conditions, the extraction yield of AXs reached up to 81.25%. Furthermore, the study determined whether water-extracted AXs (WEAXs) and enzyme-extracted AXs (E-WEAXs) from wheat flour were able to differentially stimulate nitric oxide (NO) secretion through increased levels of inducible nitric oxide synthase (iNOS) in human U937 monocytes. The results indicated that AXs concomitantly induced (P < 0.05) both NO and iNOS productions in U937 monocytes compared to untreated cells. Compared with WEAXs, E-WEAXs resulted in a higher proportion of low Mw (1–10 KDa) AXs (49.51% vs. 19.11% in WEAXs), a higher A/X ratio (0.83 vs. 0.48 in WEAXs) and a higher yield (12.83 ± 0.35% vs. 7.54 ± 0.47% in WEAXs). Moreover, E-WEAXs induced significantly (P < 0.05) greater NO and iNOS production per million viable cells (61.8 ± 2.7 μm and 42.41 ± 3.83 ng respectively) than WEAXs (51.6 ± 2.6 μm and 33.46 ± 1.48 ng, respectively). The findings suggest AXs may heighten innate immune activity in the absence of infection or disease through an iNOS-mediated stimulation of NO production. The immunomodulatory activity of the wheat-derived AXs was enhanced by enzyme treatment, with low Mw and high A/X ratio associated with elevated NO/iNOS levels in human monocytes compared to water extraction.
    • Regulation of Nitric Oxide Synthase Expression by Structure Modified Arabinoxylans from Wheat Flour in Cultured Human Monocytes

      Zhang, Zhengxiao; Smith, Christopher J.; Ashworth, Jason J.; Li, Weili; Manchester Metropolitan University; University of Chester (Wiley, 2018-01-08)
      The immunomodulatory activity of the arabinoxylans (AXs) extracts from cereal sources has been reported to impart health benefits in terms of immune enhancement. This study investigated the effect of enzymatic extraction on extraction yield and structure of AXs from wheat flour pentosan fraction. Under the optimised conditions, the extraction yield of AXs reached up to 81.25%. Furthermore, the study determined whether water-extracted AXs (WEAXs) and enzyme-extracted AXs (E-WEAXs) from wheat flour were able to differentially stimulate nitric oxide (NO) secretion through increased levels of inducible nitric oxide synthase (iNOS) in human U937 monocytes. The results indicated that AXs concomitantly induced (P < 0.05) both NO and iNOS productions in U937 monocytes compared to untreated cells. Compared with WEAXs, E-WEAXs resulted in a higher proportion of low Mw (1–10 KDa) AXs (49.51% vs. 19.11% in WEAXs), a higher A/X ratio (0.83 vs. 0.48 in WEAXs) and a higher yield (12.83 ± 0.35% vs. 7.54 ± 0.47% in WEAXs). Moreover, E-WEAXs induced significantly (P < 0.05) greater NO and iNOS production per million viable cells (61.8 ± 2.7 μm and 42.41 ± 3.83 ng respectively) than WEAXs (51.6 ± 2.6 μm and 33.46 ± 1.48 ng, respectively). The findings suggest AXs may heighten innate immune activity in the absence of infection or disease through an iNOS-mediated stimulation of NO production. The immunomodulatory activity of the wheat-derived AXs was enhanced by enzyme treatment, with low Mw and high A/X ratio associated with elevated NO/iNOS levels in human monocytes compared to water extraction.
    • The regulation of osteoprotegerin and dickkopf-1 production in osteoblastic cells

      McCarthy, Helen S. (University of ChesterCharles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry, 2011-06)
      Bone is a highly specialised living tissue and has both mechanical and metabolical functions. Remodelling of the bone ensures a healthy bone mass and is regulated by a trio of secreted proteins, namely receptor-activator of NFKB (RANK), receptor-activator of NFKB ligand (RANKL) and osteoprotegerin (OPG). OPG, a major regulator of osteoclastogenesis, bone resorption and vascular calcification, is produced by various cell types including mesenchymally derived cells, particularly osteoblastic cells. Wnt signalling also plays a role in maintaining healthy bone mass. Dickkopf- 1 (DKK-1) is a soluble inhibitor of Wnt signalling and its excessive expression contributes to bone loss in rheumatoid arthritis and multiple myeloma. Recently, NDKK-1 has been demonstrated to be over-produced in osteoblasts of patients with Paget's disease of bone (PDB). The osteoblastic cell lines MG63 and Saos-2 were subjected to a series of different growth factors, hormones and cytokines to investigate the production of OPG, DKK-1 and the expression of various Wnt proteins. These results demonstrate that during standard culture conditions, both OPG and DKK-1 production in osteoblastic cells depend on a factor present in serum. Serum deprivation resulted in the up-regulation of Wnt4 and Wnt11, while down-regulating the expression of Wnt7b. Serum-induced OPG and DKK-1 production and Wnt expression was found to be regulated via a number of different signalling pathways. OPG production and expression was stimulated by platelet-derived growth factor-AB (PDGF-AB) not only in MG63 and Saos-2 osteosarcoma cells, but also a mouse pre-osteoblastic cell line (MC3T3-E1) and human bone marrow stromal cells (BMSC). PDGF-AB was shown to act through the PDGF receptor, PKC, PI3K, ERK and P38 and not via NFKB or JNK. PDGF isoforms AA, BB and AB demonstrated a similar stimulation of OPG production. The importance of PDGF in fracture healing suggests a role for OPG production in countering bone resorption during the early phase of this process. BIO, an inhibitor of canonical Wnt signalling resulted in the down-regulation of DKK-1 and the up-regulation of WntSa. Phorbol ester (PE), a known stimulator of PKC resulted in the up-regualtion of DKK-1, Wnt4, WntTa and Wnt16. The effects of PE were inhibited by bisindolymaleamide but not staurosporine. DKK-1 production, but not expression, was observed to be stimulated by calcium along with an up-regulation of WntTb and a down-regulation of WntWa and Wnt11. Incubation of pre-stimulated cells with Triton-X demonstrated the ability of calcium to increase DKK-1 secretion. DKK-1 was shown to be significantly elevated in the serum of PDB patients compared to healthy controls and did not correlate with ALP levels. Immunohistochemistry demonstrated that DKK-1 production is increased in both osteoblasts and fibrotic cells within the marrow cavity in PDB patients compared to fracture callus. B-catenin was found to be localised to intercellular membranes of plump osteoblasts, demonstrating its alternate role as a cell adhesion protein. DKK-1 therefore may be a useful biomarker of PDB and that Dkk-1 may play a central role in the aetiology of PDB. In summary, the results presented in this thesis have investigated the ways in which OPG and DKK-1 production in osteoblastic cells can be modulated with various effectors and the effect of Wnt signalling. These results may therefore be beneficial to increase the understanding of bone biology, improve fracture repair and generate further research into the role DKK-1 and the osteoblast in the aetiology of PDB to enable improved treatments to be developed.
    • Regulation of the cell cycle and cell death by protein phosphatase 4 in breast cancer cell lines

      Mohammed, Hiba N.; Pickard, Mark R.; Williams, Gwyn T.; Mourtada-Maarabouni, Mirna; Keele University, United Kingdom (NCRI Cancer Conference 2014 Abstracts, 2014)
      Background At the molecular level, cell death is often regulated by the level of phosphorylation of particular proteins, i.e. by the balance of between opposing kinase and phosphatase activities on those proteins. Protein phosphatase 4 (PP4) is a PP2A-related serine/threonine phosphatase. PP2A has already been implicated in the control of cell proliferation, cell cycle and tumorigenesis. Using a functional expression cloning strategy, we have previously identified the catalytic subunit of PP4 (PP4c) as an important gene influencing the regulation of both apoptosis and cell proliferation in human leukaemic cell lines and in normal lymphocytes. The aims of this study were to examine the effects of PP4c overexpression and silencing on the cell death and survival of breast cancer cell lines. Method MCF7 and MDA-MB-231 cells were transfected with pcDNA3.1 encoding PP4c (pcDNA3-PP4c) or siRNAs to different PP4c sequences. Cells transfected with scrambled siRNA or empty vector were considered as controls. Culture viability, apoptosis and cell cycle were assessed post transfection. Results In MCF7 and metastatic MDA-MB-231 cells, PP4c over-expression exerted an inhibitory effect on cell proliferation, enhanced spontaneous apoptosis and decreased their colony forming ability. Conversely, siRNA mediated silencing of PP4 enhanced the proliferation and survival of MCF7 and MDA-MB-231 cells, affected cell cycle kinetics by enhancing the proportion of cells in S and G2/M phases, increased the colony forming ability and stimulated the anchorage independent growth. Conclusion PP4c promotes cell death and inhibits proliferation in breast cells, suggestive of a role of PP4c as tumour suppressor gene. Down regulation of PP4c expression increases cell survival, proliferation and anchorage independent growth of breast cancer cells, indicating a potential link between the PP4c expression levels, tumorigenesis and metastasis.
    • ‘Regurgitation and reingestion’ (R/R) in great apes: A review of current knowledge

      Hill, Sonya; University of Chester; University of Cambridge (Wiley, 2018-08-02)
      Research indicates that regurgitation and reingestion (R/R) is a relatively common behaviour in zoo-housed great apes, with most work to date carried out on Western lowland gorillas Gorilla gorilla gorilla and Chimpanzees Pan troglodytes. It is an abnormal behaviour because great apes are not anatomically adapted to regurgitate their food as part of their normal feeding processes, and because this behaviour is not seen in members of the species living freely in the wild, in conditions that would allow a full behavioural range. In this article, I give an overview of the published literature on R/R in great apes, which suggests that this behaviour is probably multifactorial and may be linked to inappropriate feeding environments (e.g. in terms of nutritional composition of the diet and/or presentation of food), and possibly also social and other factors as well. A similar behaviour to R/R, known as rumination disorder, can also occur in another great ape species, humans, in whom it is classified as a feeding and eating disorder, and there are potential consequences to people’s physical health as a result of oral acid. There have been no known studies to date to identify whether or not similar health consequences can occur in non-human great apes, but the regurgitant has been found to be significantly more acidic in gorillas than the food they ingested originally, meaning it is potentially injurious in non-human great apes. There is much that is not yet known about this behaviour and how to reduce or eliminate it when it does occur, as the research indicates that there are a range of factors involved, and these can vary by individual animal. More research into this behaviour is clearly needed to ensure that zoos and sanctuaries are providing the best possible care for these animals, and I make some suggestions for future research directions.
    • Related flavonoids cause cooperative inhibition of the sarcoplasmic reticulum Ca²⁺ ATPase by multimode mechanisms.

      Ogunbayo, Oluseye A.; Michelangeli, Francesco; University of Birmingham (Wiley, 2014-01-27)
      Flavonoids are group of plant-derived hydroxylated polycyclic molecules found in fruit and vegetables. They are known to bio-accumulate within humans and are considered to have beneficial health effects, including cancer chemoprotection. One mechanism proposed to explain this is that they are able to induce apoptosis in cancer cells by inhibiting a variety of kinases and also the Ca²⁺ ATPase. An investigation was undertaken with respect to the mechanism of inhibition for three flavonoids: quercetin, galangin and 3,6 dihydroxyflavone (3,6-DHF). Each inhibited the Ca²⁺ ATPase with K(i) values of 8.7, 10.3 and 5.4 μM, respectively, showing cooperative inhibition with n ~ 2. Given their similar structures, the flavonoids showed several differences in their mechanisms of inhibition. All three flavonoids stabilized the ATPase in the E₁ conformation and reduced [³²P]-ATP binding. However, both galangin and 3,6-DHF increased the affinity of Ca²⁺ for the ATPase by decreasing the Ca²⁺-dissociation rate constant, whereas quercetin had little effect. Ca²⁺-induced changes in tryptophan fluorescence levels were reduced in the presence of 3,6-DHF and galangin (but not with quercetin), indicating that Ca²⁺-associated changes within the transmembrane helices are altered. Both galangin and quercetin reduced the rates of ATP-dependent phosphorylation and dephosphorylation, whereas 3,6-DHF did not. Modelling studies suggest that flavonoids could potentially bind to two sites: one directly where nucleotides bind within ATP binding site and the other at a site close by. We hypothesize that interactions of these two neighbouring sites may account for both the cooperative inhibition and the multimode mechanisms of action seen with related flavonoids.
    • The Relationship Between Match-Play Characteristics of Elite Rugby League and Indirect Markers of Muscle Damage

      Oxendale, Chelsea; Twist, Craig; Daniels, Matthew; Highton, Jamie M.; University of Chester; St Helens Rugby League Club (Human Kinetics, 2016)
      Purpose: Whilst exercise-induced muscle damage (EIMD) after a rugby league match has been well documented, the specific match actions that contribute to EIMD are unclear. Accordingly, the purpose of this study was to examine the relationship between the physical demands of elite rugby league matches and subsequent EIMD. Methods: Twenty-eight performances were captured using 10 Hz global positioning systems. Upper and lower body neuromuscular fatigue, creatine kinase (CK) and perceived muscle soreness were assessed 24 h before and at 12, 36 and 60 h after a competitive match. Results: High-intensity running was moderately higher in backs (6.6 ± 2.6 m•min-1) compared to forwards (5.1 ± 1.6 m•min-1), whereas total collisions were moderately lower (31.1 ± 13.1 cf. 54.1 ± 37.0). Duration (r = 0.9, CI: 0.77 to 0.96), total distance covered (r = 0.86, CI: 0.7 to 0.95) and distance covered over 18 km•h-1 (r = 0.76, CI: 0.51 to 0.91) were associated with increased CK concentration post-match. Total collisions and repeated high-intensity efforts (RHIE) were associated with large decrements in upper body neuromuscular performance (r = -0.48, CI: -0.74 to 0.02 and r = -0.49, CI: -0.77 to 0.05, respectively), muscle soreness (r = -0.68, CI: -0.87 to -0.1 and r = -0.66, CI: -0.89 to 0.21, respectively), and CK concentration (r = 0.67, CI: 0.42 to 0.85 and r = 0.73, CI: 0.51 to 0.87, respectively). Conclusion: Match duration, high-intensity running and collisions were associated with variations in EIMD markers, suggesting recovery is dependent on individual match demands.
    • The relationship between physical abilities, ball-carrying and tackling among elite youth rugby league players

      Waldron, Mark; Worsfold, Paul R.; Twist, Craig; Lamb, Kevin L.; University of Chester (Taylor & Francis, 2013-09-27)
      This study investigated the relationship between the physical abilities of adolescent rugby league players and tackling and ball-carrying skills performed during matches, across three seasons (under-15 to under-17). The players were measured each season for acceleration (10–30 m), peak and mean speed (10–30 m), sprinting force (10–30 m), aerobic power, counter-movement jump (CMJ) height and jumping power. The matches were filmed and analysed for ball-carrying and tackling frequency per minute (successful and unsuccessful outcomes). There were strong relationships between successful carries∙min–1 and 10 m force in the under-15 (R = 0.61, P < 0.001), under-16 (R = 0.69, P < 0.001) and under-17 groups (R = 0.64, P < 0.001). There were also strong and moderate relationships between predicted vertical power and successful carries∙min–1 in the under-15 (R = 0.63, P = 0.011) and under-17 group (R = 0.40, P = 0.030), respectively. There were no relationships between carries or tackles and any other performance indicators. These findings suggest that acceleration, in accordance with gains in body mass, support ball-carrying but not tackling performance. Performance measurements, such as CMJ or aerobic power, do not support ball-carrying ability among youth rugby league players.
    • Release of coumarin encapsulated in chitosan-gelatin irradiated films

      Benbettaïeb, Nasreddine; Chambin, Odile; Assifaoui, Ali; Al-Assaf, Saphwan; Karbowiak, Thomas; Debeaufort, Frédéric; Phillips Hydrocolloids Research Centre, Glyndwr University, Wrexham LL11 2AW, UK (Elsevier, 2015-12-24)
      Chitosan and fish gelatin were used to formulate active biobased films containing an antioxidant (coumarin). After drying, the films were irradiated at 40 and 60 kGy using an electron beam accelerator. The effect of irradiation on the film properties as well as the coumarin release mechanism were investigated and compared with the control. Electron Spin Resonance (ESR) revealed free radical formation during irradiation in films containing coumarin. Antioxidant addition and/or irradiation treatment at a dose of 60 kGy resulted in a shift of amide A and amide B peaks. Furthermore a shift of amide II band was only observed for the control film at the same dose. Irradiation allowed improving the thermal stability of the control films. Both irradiation process and addition of coumarin increased the surface wettability (increase of the polar component of the surface tension). From the water barrier analysis, neither irradiation nor coumarin addition influenced the permeability at the lower RH gradient used (0e30% RH). Using the higher RH gradient (30e84%) induced a rise of the WVP of all films (containing or not coumarin) after irradiation treatment. At 60 kGy, the tensile strength of only the control films increased significantly. Considering coumarin release from the film in aqueous medium, the apparent diffusion coefficient of coumarin is two times reduced after irradiation. Irradiation also allowed to better protect the incorporated antioxidant. Indeed, the amount of coumarin in the non-irradiated film was significantly lowered compared to the initial quantity, which is probably due to chemical reactivity.
    • The Reliability and Validity of A Submaximal Warm-Up Test for Monitoring Training Status in Professional Soccer Players.

      Rabbani, Alizera; Kargarfard, Mehdi; Twist, Craig; University of Isfahan; University of Chester (Lippincott, Williams & Wilkins, 2017-11-27)
      Two studies were conducted to assess the reliability and validity of a submaximal warm-up test (SWT) in professional soccer players. For the reliability study, 12 male players performed SWT over three trials, with one week between trials. For the validity study, 14 players of the same team performed SWT and 30-15 Intermittent Fitness Test (30-15IFT) 7 days apart. Week-to-week reliability in selected heart rate (HR) responses [exercise HR (HRex), HR recovery (HRR) expressed as the number of beats recovered within 1 min (HRR60s) and expressed as the mean HR during 1 min (HRpost1)], were determined using intraclass correlation coefficient (ICC) and typical error of measurement expressed as coefficient of variation (CV). The relationships between HR measures derived from SWT and the maximal speed reached at the 30-15IFT (VIFT) were used to assess validity. The range for ICC and CV values were 0.83 to 0.95 and 1.4 to 7.0% in all HR measures, respectively, with the HRex as the most reliable HR measure of SWT. Inverse large (r = -0.50, 90% confidence limits, CL (-0.78; -0.06)) and very large (r = -0.76, CL, -0.90; -0.45) relationships were observed between HRex and HRpost1 with VIFT in relative (expressed as the % of maximal HR) measures, respectively. SWT is a reliable and valid submaximal test to monitor high-intensity intermittent running fitness in professional soccer players. In addition, the test’s short duration (5-min) and simplicity mean that it can be used regularly to assess training status in high-level soccer players.
    • The reliability and validity of short-distance sprint performance assessed on a nonmotorized treadmill

      Highton, Jamie M.; Lamb, Kevin L.; Twist, Craig; Nicholas, Ceri; University of Chester (National Strength and Conditioning Association, 2012)
      This study examined the interday and intraday reliabilities and validities of various sprint performance variables on a nonmotorized treadmill (NMT) over distances of 10, 20, and 30 metres.
    • The reliability of Functional Movement Screening (FMS) and in-season changes in physical function and performance among elite rugby league players

      Waldron, Mark; Gray, Adrian; Worsfold, Paul R.; Twist, Craig; University of New England, Australia ; University of New England, Australia ; University of Chester ; University of Chester (Lippincott, Williams & Wilkins, 2014-03-26)
      Functional Movement Screening (FMS) comprises seven tests that assess fundamental movement characteristics of athletes. However, the reliability of the FMS protocol and its sensitivity to changes in physical performance has not been appropriately investigated. Accordingly, this study aimed to assess the real-time reliability of the FMS protocol and to establish changes in both FMS and tests of physical performance throughout a season. The reliability of the FMS components (12 in total) were assessed via a non-parametric statistical approach, based on two trials, separated by one week. Score on the FMS, strength (3 RM full squat, 1 RM bench press), running speed (10 & 40 m) and jump height of 12 elite male under-19 rugby league players was monitored at pre-, mid- and late-season periods. There was no bias found between trials for the FMS, with the majority of components reaching 100% ‘perfect agreement’. There were no effects of season stage on any of the FMS components; however, an improvement in every performance test was apparent between the pre- and both mid- and late-season periods. Our findings demonstrate that the FMS can be reliably administered to elite rugby league players but question its sensitivity to systematic changes in athletic performance.
    • Reliability of ratings of perceived exertion during progressive treadmill exercise.

      Lamb, Kevin L.; Eston, Roger; Corns, David; University College Chester (Elsevier, 1999-10)
      OBJECTIVE: To assess the test-retest reliability (repeatability) of Borg's 6-20 rating of perceived exertion (RPE) scale using a more appropriate statistical technique than has been employed in previous investigations. The RPE scale is used widely in exercise science and sports medicine to monitor and/or prescribe levels of exercise intensity. The "95% limits of agreement" technique has recently been advocated as a better means of assessing within-subject (trial to trial) agreement than traditional indicators such as Pearson and intraclass correlation coefficients. METHODS: Sixteen male athletes (mean (SD) age 23.6 (5.1) years) completed two identical multistage (incremental) treadmill running protocols over a period of two to five days. RPEs were requested and recorded during the final 15 seconds of each three minute stage. All subjects successfully completed at least four stages in each trial, allowing the reliability of RPE responses to be examined at each stage. RESULTS: The 95% limits of agreement (bias +/- 1.96 x SDdiff) were found to widen as exercise intensity increased: 0.88 (2.02) RPE units (stage 1), 0.25 (2.53) RPE units (stage 2), -0.13 (2.86) RPE units (stage 3), and -0.13 (2.94) RPE units (stage 4). Pearson correlations (0.81, 0.72, 0.65, and 0.60) and intraclass correlations (0.82, 0.80, 0.77, and 0.75) decreased as exercise intensity increased. CONCLUSIONS: These findings question the test-retest reliability of the RPE scale when used to monitor subjective estimates of exercise intensity in progressive (or graded) exercise tests.
    • The reliability of tests for sport-specific skill amongst elite youth rugby league players

      Waldron, Mark; Worsfold, Paul R.; Twist, Craig; Lamb, Kevin L.; University of Chester (Taylor & Francis, 2012-08-10)
      In rugby league, tests of sport-specific skill often involve subjective assessments of performance by observers of varying qualification. However, the reliability of such subjective assessments has yet to be investigated via appropriate statistical techniques. Therefore, the aims of the current study were to investigate: (1) the intra-observer reliability of a non-qualified observer (‘novice’) and (2) the inter-observer reliability of the three observers (two qualified ‘experts’ and one novice observer) in the assessment of catching, passing and tackling (stages 1 and 2) ability in elite adolescent rugby league players (age: 14.790.5 years). Players performed each skill element within a simulated practice drill and were assessed in ‘real time’ by the observers according to pre-defined criteria. An overall bias (PB0.05) was revealed between the observers in stage 1 of catching and stage 1 of passing, the differences being higher for the novice compared to both expert coaches for each stage of catching and the first stage of passing, and between expert 2 and the novice for stage 2 of tackling. No comparisons met the pre-determined analytical goal of ‘perfect agreement’, for any of the skill components. Comparisons between the expert observers did not reach perfect agreement, with the lowest values occurring for both tackling skill stages (60 65%). None of the tests employed were sufficiently reliable to potentially discern between players of differing ability, which may mean up to 56% of players’ skill being misinterpreted. The credibility of such assessments should be questioned and alternative tests considered.