• Nicotinic α7 and α4β2 agonists enhance the formation and retrieval of recognition memory: potential mechanisms for cognitive performance enhancement in neurological and psychiatric disorders

      McLean, Samantha L.; Grayson, Ben; Marsh, S.; Zarroug, S.H.O.; Harte, Michael K.; Neill, Joanna C. (2016)
      Cholinergic dysfunction has been shown to be central to the pathophysiology of Alzheimer’s disease and has also been postulated to contribute to cognitive dysfunction observed in various psychiatric disorders, including schizophrenia. Deficits are found across a number of cognitive domains and in spite of several attempts to develop new therapies, these remain an unmet clinical need. In the current study we investigated the efficacy of donepezil, risperidone and selective nicotinic α7 and α4β2 receptor agonists to reverse a delay-induced deficit in recognition memory. Adult female Hooded Lister rats received drug treatments and were tested in the novel object recognition (NOR) task following a 6 h inter-trial interval (ITI). In all treatment groups, there was no preference for the left or right identical objects in the acquisition trial. Risperidone failed to enhance recognition memory in this paradigm whereas donepezil was effective such that rats discriminated between the novel and familiar object in the retention trial following a 6 h ITI. Although a narrow dose range of PNU-282987 and RJR- 2403 was tested, only one dose of each increased recognition memory, the highest dose of PNU-282987 (10 mg/kg) and the lowest dose of RJR-2403 (0.1 mg/kg), indicative of enhanced cognitive performance. Interestingly, these compounds were also efficacious when administered either before the acquisition or the retention trial of the task, suggesting an important role for nicotinic receptor subtypes in the formation and retrieval of recognition memory.
    • The Nikumaroro bones identification controversy: First-hand examination versus evaluation by proxy — Amelia Earhart found or still missing?

      Cross, Pamela J.; Wright, R. (2015-09)
      American celebrity aviator Amelia Earhart was lost over the Pacific Ocean during her press-making 1937 round-the-world flight. The iconic woman pilot remains a media interest nearly 80 years after her disappearance, with perennial claims of finds pinpointing her location. Though no sign of the celebrity pilot or her plane have been definitively identified, possible skeletal remains have been attributed to Earhart. The partial skeleton was recovered and investigated by British officials in 1940. Their investigation concluded that the remains were those of a stocky, middle-aged male. A private historic group re-evaluated the British analysis in 1998 as part of research to establish Gardner (Nikumaroro) Island as the crash site. The 1998 report discredited the British conclusions and used cranial analysis software (FORDISC) results to suggest that the skeleton was potentially a Northern European woman, and consistent with Amelia Earhart. A critical review of both investigations and contextual evidence shows that the original British osteological analyses were made by experienced, reliable professionals, while the cranial analysis is unreliable given the available data. Without access to the missing original bones, it is impossible to be definitive, but on balance, the most robust scientific analysis and conclusions are those of the original British finding indicating that the Nikumaroro bones belonged to a robust, middle-aged man, not Amelia Earhart.
    • Nipple aspirate fluid - a liquid biopsy for diagnosing breast health

      Shaheed, Sadr-ul; Tait, C.; Kyriacou, K.; Mullarkey, J.; Burrill, W.; Patterson, Laurence H.; Linforth, R.; Salhab, M.; Sutton, Chris W. (2017)
      Purpose: Nipple secretions are protein-rich and a potential source of breast cancer biomarkers for breast cancer screening. Previous studies of specific proteins have shown limited correlation with clinicopatholigical features. Our aim, in this pilot study, was to investigate the intra- and inter-patient protein composition of nipple secretions and the implications for their use as liquid biopsies. Experimental design: Matched pairs of NAF (n=15) were characterised for physicochemical properties and SDS PAGE. Four pairs were selected for semi-quantitative proteomic profiling and trypsin-digested peptides analysed using 2D LC Orbitrap Fusion mass spectrometry. The resulting data was subject to bioinformatics analysis and statistical evaluation for functional significance. Results: A total of 1990 unique proteins were identified many of which are established cancer associated markers. Matched pairs shared the greatest similarity (average Pearson correlation coefficient of 0.94), but significant variations between individuals was observed. Conclusions: This was the most complete proteomic study of NAF to date providing a valuable source for biomarker discovery. The high level of milk proteins in healthy volunteer samples compared to the cancer patients was associated with galactorrhoea. Using matched pairs increased confidence in patient-specific protein levels but changes relating to cancer stage require investigation of a larger cohort.
    • Nitric oxide formation during cortical spreading depression is critical for rapid subsequent recovery of ionic homeostasis

      Urenjak, Jutta A.; Obrenovitch, Tihomir P.; Wang, M. (2009-07-27)
      Cortical spreading depression (CSD) is a temporary disruption of local ionic homeostasis that propagates slowly across the cerebral cortex. Cortical spreading depression promotes lesion progression in experimental stroke, and may contribute to the initiation of migraine attacks. The purpose of this study was to investigate the roles of the marked increase of nitric oxide (NO) formation that occurs with CSD. Microdialysis electrodes were implanted in the cortex of anesthetized rats to perform the following operations within the same region: (1) elicitation of CSD by perfusion of high K+ medium; (2) recording of CSD elicitation; (3) application of the NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME); and (4) recording of dialysate pH changes. The primary effect of L-NAME (0.3 to 3.0 mmol/L in the perfusion medium) was a marked widening of individual CSD wave, resulting essentially from a delayed initiation of the repolarization phase. This change was due to NO synthase inhibition because it was not observed with the inactive isomer D-NAME, and was reversed by L-arginine. This effect did not appear to be linked to the suppression of a sustained, NO-mediated vascular change associated with the superposition of NO synthase inhibition on high levels of extracellular K+. The delayed initiation of repolarization with local NO synthase inhibition may reflect the suppression of NO-mediated negative feedback mechanisms acting on neuronal or glial processes involved in CSD genesis. However, the possible abrogation of a very brief, NO-mediated vascular change associated with the early phase of CSD cannot be ruled out.
    • Nitrofurantoin-melamine monohydrate (cocrystal hydrate): Probing the role of H-bonding on the structure and properties using quantum chemical calculations and vibrational spectroscopy

      Khan, E.; Shukla, A.; Jhariya, Aditya N.; Tandon, P.; Vangala, Venu R. (2019-10-05)
      Cocrystal monohydrate of nitrofurantoin (NF) with melamine (MELA) has been studied as NF is an antibacterial drug used for the treatment of urinary tract infections. The structure of nitrofurantoin-melamine-monohydrate (NF-MELA-H2O) is characterized by FT-IR and FT-Raman spectroscopy. The energies and vibrational frequencies of the optimized structures calculated using quantum chemical calculations. Supported by normal coordinate analyses and potential energy distributions (PEDs), the complete vibrational assignments recommended for the observed fundamentals of cocrystal hydrate. With the aim of inclusion of all the H-bond interactions, dimer of NF-MELA-H2O has been studied as only two molecules of cocrystal hydrate are present in the unit cell. By the study of dimeric model consistent assignment of the FT-IR and FT-Raman spectrum obtained. H-bonds are of essential importance in an extensive range of molecular sciences. The vibrational analyses depict existence of H-bonding (O-H⋯N) between water O-H and pyridyl N atom of MELA in both monomer and dimer. To probe the strength and nature of H-bonding in monomer and dimer, topological parameters such as electron density (ρBCP), Laplacian of electron density (∇2ρBCP), total electron energy density (HBCP) and H-bond energy (EHB) at bond critical points (BCP) are evaluated by quantum theory of atoms in molecules (QTAIM). Natural bond orbitals (NBOs) analyses are carried out to study especially the intra and intermolecular H-bonding and their second order stabilization energy (E(2)). The value of HOMO-LUMO energy band gap for NF-MELA-H2O (monomer and dimer both) is less than NF, showing more chemical reactivity for NF-MELA-H2O. Chemical reactivity has been described with the assistance of electronic descriptors. Global electrophilicity index (ω = 7.3992 eV) shows that NF-MELA-H2O behaves as a strong electrophile than NF. The local reactivity descriptors analyses such as Fukui functions, local softnesses and electrophilicity indices performed to determine the reactive sites within NF-MELA-H2O. In MEP map of NF-MELA (monomer and dimer) electronegative regions are about NO2 and C=O group of NF, although the electropositive regions are around NH2, N-H group and H2O molecule. Molar refractivity (MR) value of NF-MELA-H2O (monomer and dimer) lies within the range set by Lipinski's modified rules. This study could set as an example to study the H-bond interactions in pharmaceutical cocrystals.
    • NMDA receptor-dependent signalling pathways regulate arginine vasopressin expression in the paraventricular nucleus of the rat

      Lake, D.; Corrêa, Sonia A.L.; Müller, Jurgen (2019-11-01)
      The antidiuretic hormone arginine vasopressin (AVP) regulates water homeostasis, blood pressure and a range of stress responses. It is synthesized in the hypothalamus and released from the posterior pituitary into the general circulation upon a range of stimuli. While the mechanisms leading to AVP secretion have been widely investigated, the molecular mechanisms regulating AVP gene expression are mostly unclear. Here we investigated the neurotransmitters and signal transduction pathways that activate AVP gene expression in the paraventricular nucleus (PVN) of the rat using acute brain slices and quantitative real-time PCR. We show that stimulation with l-glutamate robustly induced AVP gene expression in acute hypothalamic brain slices containing the PVN. More specifically, we show that AVP transcription was stimulated by NMDA. Using pharmacological treatments, our data further reveal that the activation of ERK1/2 (PD184352), CaMKII (KN-62) and PI3K (LY294002; 740 Y-P) is involved in the NMDA-induced AVP gene expression in the PVN. Together, this study identifies NMDA-mediated cell signalling pathways that regulate AVP gene expression in the rat PVN.
    • No Margins, No Word Counts, No Masters! Experimenting With 'Zines for Archaeological Outreach

      Fitzpatrick, Alexandra L. (2019-01)
      Alternative forms of information dissemination have always been a crucial part of many radical forms of activism and organization. Arguably the most famous is the ‘zine - popularized in the punk/anarchist subculture of the 1980’s and 90’s, ‘zines were the antithesis of mainstream magazines, journals, and periodicals. They were an extension of the D.I.Y. (do-it-yourself) attitude that flourished within the subculture, reflecting a more informal and individualistic approach to the dissemination of information and ideas without the rigid formalities of mainstream literature. With the emergence of a new countercultural led by millennials, ‘zines have once again found popularity, taking advantage of the Internet to spread information even further than before through digital means. Although all ‘zines are different due to the individualistic and free nature of the format, most are often educational texts that also incorporate other forms of writing and media to help engage its audience with its content in a more exciting and entertaining way. Unfortunately, it appears that ‘zines have yet to find a foothold in academia as they have in social justice and activist groups – this is a shame, as there is a wealth of possibilities for the application of a ‘zine format for the dissemination of information to non-specialist audiences. This paper explores the idea of utilizing ‘zines as an alternative approach to public outreach in archaeology. This will include documenting and reflecting on the current progress of a ‘zine being developed by myself and other archaeologists about anarchist approaches to archaeological theory and practice. I will examine how practical it is to adopt this method for outreach, compare it to the more "traditional" methods of dissemination (journals, conferences, etc.), and reflect on my personal experiences with creating an archaeological 'zine of my own.
    • Noggin overexpression inhibits eyelid opening by altering epidermal apoptosis and differentiation.

      Sharov, A.A.; Weiner, L.; Sharova, T.Y.; Siebenhaar, F.; Atoyan, R.; Reginato, A.M.; McNamara, C.A.; Funa, K.; Gilchrest, B.A.; Brissette, J.L.; et al. (2003)
      Contact of developing sensory organs with the external environment is established via the formation of openings in the skin. During eye development, eyelids first grow, fuse and finally reopen, thus providing access for visual information to the retina. Here, we show that eyelid opening is strongly inhibited in transgenic mice overexpressing the bone morphogenetic protein (BMP) antagonist noggin from the keratin 5 (K5) promoter in the epidermis. In wild-type mice, enhanced expression of the kinase-inactive form of BMPR-IB mediated by an adenovirus vector also inhibits eyelid opening. Noggin overexpression leads to reduction of apoptosis and retardation of cell differentiation in the eyelid epithelium, which is associated with downregulation of expression of the apoptotic receptors (Fas, p55 kDa TNFR), Id3 protein and keratinocyte differentiation markers (loricrin, involucrin). BMP-4, but not EGF or TGF-, accelerates opening of the eyelid explants isolated from K5-Noggin transgenic mice when cultured ex vivo. These data suggest that the BMP signaling pathway plays an important role in regulation of genetic programs of eyelid opening and skin remodeling during the final steps of eye morphogenesis.
    • Non-antibiotic quorum sensing inhibitors acting against N-acyl homoserine lactone synthase as druggable target

      Chang, Chien-Yi; Krishnan, T.; Wang, H.; Chen, Y.; Yin, W.; Chong, Y.; Tan, L.Y.; Chong, T.M.; Chan, K. (2014-11)
      N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography–mass spectrometry (LCMS). These AHL-producing E. coli served as tools for screening AHL synthase inhibitors. Based on a campaign of screening synthetic molecules and natural products using our approach, three strongest inhibitors namely are salicylic acid, tannic acid and trans-cinnamaldehyde have been identified. LCMS analysis further confirmed tannic acid and trans-cinnemaldehyde efficiently inhibited AHL production by RhlI. We further demonstrated the application of trans-cinnemaldehyde inhibiting Rhl QS system regulated pyocyanin production in P. aeruginosa up to 42.06%. Molecular docking analysis suggested that trans-cinnemaldehyde binds to the LasI and EsaI with known structures mainly interacting with their substrate binding sites. Our data suggested a new class of QS-inhibiting agents from natural products targeting AHL synthase and provided a potential approach for facilitating the discovery of anti-QS signal synthesis as basis of novel anti-infective approach.
    • Non-covalent adsorption of amino acid analogues on noble-metal nanoparticles: influence of edges and vertices

      Hughes, Zak E.; Walsh, T.R. (2016)
      The operation of many nanostructured biomolecular sensors and catalysts critically hinges on the manipulation of non-covalent adsorption of biomolecules on unfunctionalised noble-metal nanoparticles (NMNPs). Molecular-level structural details of the aqueous biomolecule/NMNP interface are pivotal to the successful realisation of these technologies, but such experimental data are currently scarce and challenging to obtain. Molecular simulations can generate these details, but are limited by the assumption of non-preferential adsorption to NMNP features. Here, via first principles calculations using a vdW-DF functional, and based on nanoscale sized NMNPs, we demonstrate that adsorption preferences to NP features vary with adsorbate chemistry. These results show a clear distinction between hydrocarbons, that prefer adsorption to facets over edges/vertices, over heteroatomic molecules that favour adsorption onto vertices over facets. Our data indicate the inability of widely used force-fields to correctly capture the adsorption of biomolecules onto NMNP surfaces under aqueous conditions. Our findings introduce a rational basis for the development of new force-fields that will reliably capture these phenomena.
    • A Non-invasive 2D Digital Imaging Method for Detection of Surface Lesions Using Machine Learning

      Hussain, Nosheen; Cooper, Patricia A.; Shnyder, Steven D.; Ugail, Hassan; Bukar, Ali M.; Connah, David (2017)
      As part of the cancer drug development process, evaluation in experimental subcutaneous tumour transplantation models is a key process. This involves implanting tumour material underneath the mouse skin and measuring tumour growth using calipers. This methodology has been proven to have poor reproducibility and accuracy due to observer variation. Furthermore the physical pressure placed on the tumour using calipers is not only distressing for the mouse but could also lead to tumour damage. Non-invasive digital imaging of the tumour would reduce handling stresses and allow volume determination without any potential tumour damage. This is challenging as the tumours sit under the skin and have the same colour pattern as the mouse body making them hard to differentiate in a 2D image. We used the pre-trained convolutional neural network VGG-16 and extracted multiple layers in an attempt to accurately locate the tumour. When using the layer FC7 after RELU activation for extraction, a recognition rate of 89.85% was achieved.
    • Non-medical prescribing in palliative care: a regional survey

      Ziegler, Lucy; Bennett, M.; Blenkinsopp, Alison; Coppock, S. (2015-02)
      The United Kingdom is considered to be the world leader in nurse prescribing, no other country having the same extended non-medical prescribing rights. Arguably, this growth has outpaced research to evaluate the benefits, particularly in areas of clinical practice where patients have complex co-morbid conditions such as palliative care. This is the first study of non-medical prescribing in palliative care in almost a decade. AIM: To explore the current position of nurse prescribing in palliative care and establish the impact on practice of the 2012 legislative changes. DESIGN: An online survey circulated during May and June 2013. PARTICIPANTS: Nurse members (n = 37) of a regional cancer network palliative care group (61% response rate). RESULTS: While this survey found non-medical prescribers have embraced the 2012 legislative changes and prescribe a wide range of drugs for cancer pain, we also identified scope to improve the transition from qualified to active non-medical prescriber by reducing the time interval between the two. CONCLUSION: To maximise the economic and clinical benefit of non-medical prescribing, the delay between qualifying as a prescriber and becoming an active prescriber needs to be reduced. Nurses who may be considering training to be a non-medical prescriber may be encouraged by the provision of adequate study leave and support to cover clinical work. Further research should explore the patients' perspective of non-medical prescribing.
    • A non-randomised feasibility study of an intervention to optimise medicines at transitions of care for patients with heart failure

      Fylan, Beth; Ismail, Hanif; Hartley, S.; Gale, C.P.; Farrin, A.J.; Gardner, Peter H.; Silcock, Jonathan; Alldred, David P. (2021-03)
      Heart failure affects 26 million people globally, and the optimal management of medicines is crucial for patients, particularly when their care is transferred between hospital and the community. Optimising clinical outcomes requires well-calibrated cross-organisational processes with staff and patients responding and adapting to medicines changes. The aim of this study was to assess the feasibility of implementing a complex intervention (the Medicines at Transitions Intervention; MaTI) co-designed by patients and healthcare staff. The purpose of the intervention was to optimise medicines management across the gaps between secondary and primary care when hospitals handover care. The study objectives were to (1) assess feasibility through meeting specified progression criteria to proceed to the trial, (2) assess if the intervention was acceptable to staff and patients, and (3) determine whether amendment or refinement would be needed to enhance the MaTI. The feasibility of the MaTI was tested in three healthcare areas in the North of England between July and October 2017. Feasibility was measured and assessed through four agreed progression to trial criteria: (1) patient recruitment, (2) patient receipt of a medicines toolkit, (3) transfer of discharge information to community pharmacy, and (4) offer of a community pharmacy medicines review/discussion or medicines reconciliation. From the cardiology wards at each of the three NHS Acute Trusts (sites), 10 patients (aged ≥ 18 years) were recruited and introduced to the 'My Medicines Toolkit' (MMT). Patients were asked to identify their usual community pharmacy or nominate a pharmacy. Discharge information was transferred to the community pharmacy; pharmacists were asked to reconcile medicines and invited patients for a medicines use review (MUR) or discussion. At 1 month following discharge, all patients were sent three questionnaire sets: quality-of-life, healthcare utilisation, and a patient experience survey. In a purposive sample, 20 patients were invited to participate in a semi-structured interview about their experiences of the MaTI. Staff from hospital and primary care settings involved in patients' care were invited to participate in a semi-structured interview. Patient and staff interviews were analysed using Framework Analysis. Questionnaire completion rates were recorded and data were descriptively analysed. Thirty-one patients were recruited across three sites. Eighteen staff and 18 patients took part in interviews, and 19 patients returned questionnaire sets. All four progression to trial criteria were met. We identified barriers to patient engagement with the intervention in hospital, which were compounded by patients' focus on returning home. Some patients described not engaging in discussions with staff about medicines and lacking motivation to do so because they were preoccupied with returning home. Some patients were unable or unwilling to attend a community pharmacy in person for a medicines review. Roles and responsibilities for delivering the MaTI were different in the three sites, and staff reported variations in time spent on MaTI activities. Staff reported some work pressures and staff absences that limited the time they could spend talking to patients about their medicines. Clinical teams reported that recording a target dose for heart failure medicines in patient-held documentation was difficult as they did not always know the ideal or tolerable dose. The majority of patients reported receiving the patient-held documentation. More than two-thirds reported being offered a MUR by their community pharmacists. Delivery of the Medicines at Transitions Intervention (MaTI) was feasible at all three sites, and progression to trial criteria were met. Refinements were found to be necessary to overcome identified barriers and strengthen delivery of all steps of the intervention. Necessary changes to the MaTI were identified along with amendments to the implementation plan for the subsequent trial. Future implementation needs to take into account the complexity of medicines management and adaptation to local context.
    • Non-veridical visual perception in human amblyopia

      Pacey, Ian E.; Barrett, Brendan T.; Bradley, A.; Thibos, L.N. (2003)
      PURPOSE. Amblyopia is a developmental disorder of spatial vision. There is evidence to suggest that some amblyopes misperceive spatial structure when viewing with the affected eye. However, there are few examples of these perceptual errors in the literature. This study was an investigation of the prevalence and nature of misperceptions in human amblyopia. METHODS. Thirty amblyopes with strabismus and/or anisometropia participated in the study. Subjects viewed sinusoidal gratings of various spatial frequencies, orientations, and contrasts. After interocular comparison, subjects sketched the subjective appearance of those stimuli that had nonveridical appearances. RESULTS. Nonveridical visual perception was revealed in 20 amblyopes (~67%). In some subjects, misperceptions were present despite the absence of a deficit in contrast sensitivity. The presence of distortions was not simply linked to the depth of amblyopia, and anisometropes were affected as well as those with strabismus. In most cases, these spatial distortions arose at spatial frequencies far below the contrast detection acuity cutoff. Errors in perception became more severe at higher spatial frequencies, with low spatial frequencies being mostly perceived veridically. The prevalence and severity of misperceptions were frequently found to depend on the orientation of the grating used in the test, with horizontal orientations typically less affected than other orientations. Contrast had a much smaller effect on misperceptions, although there were cases in which severity was greater at higher contrasts. CONCLUSIONS. Many types of misperceptions documented in the present study have appeared in previous investigations. This suggests that the wide range of distortions previously reported reflect genuine intersubject differences. It is proposed that nonveridical perception in human amblyopia has its origins in errors in the neural coding of orientation in primary visual cortex.
    • Nonadiabatic transition-state theory: A Monte Carlo Study of competing bond fission processes in bromoacetyl chloride

      Marks, Alison J. (2001)
      Nonadiabatic Monte Carlo transition-state theory is used to explore competing C¿Cl and C¿Br bond fission processes in a simple model of 1[n,pi*(CO)] photoexcited bromoacetyl chloride. Morse potentials are used to represent bond stretching coordinates, and the positions and magnitudes of nonadiabatic coupling between excited state potentials are modeled using ab initio data. The main effect of nonadiabaticity is to favor C¿Cl fission over C¿Br, despite a larger barrier to C¿Cl dissociation. The absolute values of the rate constants are smaller than observed experimentally, but the calculated branching ratios are close to the experimental value. For C¿Cl fission, it is shown that the minimum energy crossing point is not sufficient to describe the rate constant, suggesting that care must be taken when using alternative models which make this assumption.
    • A nordehydroabietyl amide-containing chiral diene for rhodium-catalysed asymmetric arylation to nitroolefins

      Li, R.; Wen, Z.; Wu, Na (Anna) (2016-12)
      A highly enantioselective rhodium catalysed asymmetric arylation (RCAA) of nitroolefins with arylboronic acids is presented using a newly developed, C1-symmetric, non-covalent interacted, phellandrene derived, nordehydroabietyl amide-containing chiral diene under mild conditions. Stereoelectronic effects were studied, suggesting an activation of the bound substrate through the secondary amide as a hydrogen-bond donor.
    • Normal values and test-retest variability of stimulated-echo diffusion tensor imaging and fat fraction measurements in the muscle

      Farrow, Matthew; Grainger, A.J.; Tan, A.L.; Buch, M.H.; Emery, P.; Ridgway, J.P.; Feiweier, T.; Tanner, S.F.; Biglands, J. (2019-09)
      Objectives: To assess the test-retest variability of both diffusion parameters and fat fraction (FF) estimates in normal muscle, and to assess differences in normal values between muscles in the thigh. Methods: 29 healthy volunteers (mean age 37 years, range 20-60 years, 17/29 males) completed the study. Magnetic resonance images of the mid-thigh were acquired using a stimulated echo acquisition mode-echoplanar imaging (STEAM-EPI) imaging sequence, to assess diffusion, and 2-point Dixon imaging, to assess FF. Imaging was repeated in 19 participants after a 30 min interval in order to assess test-retest variability of the measurements. Results: Intraclass correlation coefficients (ICCs) for test-retest variability were 0.99 [95% confidence interval, (CI): 0.98, 1] for FF, 0.94 (95% CI: 0.84, 0.97) for mean diffusivity and 0.89 (95% CI: 0.74, 0.96) for fractional anisotropy (FA). FF was higher in the hamstrings than the quadriceps by a mean difference of 1.81% (95% CI:1.63, 2.00)%, p < 0.001. Mean diffusivity was significantly lower in the hamstrings than the quadriceps (0.26 (0.13, 0.39) x10-3 mm2s-1, p < 0.001) whereas fractional anisotropy was significantly higher in the hamstrings relative to the quadriceps with a mean difference of 0.063 (0.05, 0.07), p < 0.001. Conclusions: This study has shown excellent test-retest, variability in MR-based FF and diffusion measurements and demonstrated significant differences in these measures between hamstrings and quadriceps in the healthy thigh. Advances in knowledge: Test-retest variability is excellent for STEAM-EPI diffusion and 2-point Dixon-based FF measurements in the healthy muscle. Inter- and intraobserver variability were excellent for region of interest placement for STEAM-EPI diffusion and 2-point Dixon-based FF measurements in the healthy muscle. There are significant differences in FF and diffusion measurements between the hamstrings and quadriceps in the normal muscle.
    • ‘Not All That Is White Is Lime’—White Substances from Archaeological Burial Contexts: Analyses and Interpretations

      Schotsmans, Eline M.J.; Toksoy-Köksal, F.; Bretterl, Rhea C.; Bessou, M.; Corbineau, R.; Lingle, A.M.; Bouquin, D.; Blanchard, P.; Becker, K.; Castex, D.; et al. (2019-08)
      Archaeological burial contexts may include a variety of white substances, but few analyses have been published. This study reports on the physico‐chemical characterization of such residues from seven archaeological sites. It is often assumed that white materials from burial contexts are lime. Our findings demonstrate that they can be gypsum, calcite (chalk), aragonite, brushite, degraded metal, natural (gum) resins or synthetic polymer–based products. These may be present as the result of diagenetic processes, funerary practices or modern contamination. This paper provides an analytical approach for the holistic investigation of white materials encountered in burial contexts.