Recent Submissions

  • Development and validation of the vision-related dizziness questionnaire

    Armstrong, Deborah; Alderson, Alison J.; Davey, Christopher J.; Elliott, David B. (2018-05-29)
    Purpose: To develop and validate the first patient-reported outcome measure (PROM) to quantify vision-related dizziness. Dizziness is a common, multifactorial syndrome that causes reductions in quality of life and is a major risk factor for falls, but the role of vision is not well understood. Methods: Potential domains and items were identified by literature review and discussions with experts and patients to form a pilot PROM, which was completed by 335 patients with dizziness. Rasch analysis was used to determine the items with good psychometric properties to include in a final PROM, to check undimensionality, differential item functioning, and to convert ordinal questionnaire data into continuous interval data. Validation of the final 25-item instrument was determined by its convergent validity, patient, and item-separation reliability and unidimensionality using data from 223 patients plus test–retest repeatability from 79 patients. results: 120 items were originally identified, then subsequently reduced to 46 to form a pilot PROM. Rasch analysis was used to reduce the number of items to 25 to produce the vision-related dizziness or VRD-25. Two subscales of VRD-12-frequency and VRD-13-severity were shown to be unidimensional, with good psychometric properties. Convergent validity was shown by moderately good correlations with the Dizziness Handicap Inventory (r = 0.75) and good test–retest repeatability with intra-class correlation coefficients of 0.88. conclusion: VRD-25 is the only PROM developed to date to assess vision-related dizziness. It has been developed using Rasch analysis and provides a PROM for this under-researched area and for clinical trials of interventions to reduce vision-related dizziness.
  • Adherence to coronary artery disease secondary prevention medicines: exploring modifiable barriers

    Khatib, R.; Marshall, K.; Silcock, Jonathan; Forrest, C.; Hall, A.S. (2019-07)
    Background: Non-adherence to secondary prevention medicines (SPMs) among patients with coronary artery disease (CAD) remains a challenge in clinical practice. This study attempted to identify actual and potential modifiable barriers to adherence that can be addressed in cardiology clinical practice. Methods: This was a cross-sectional, postal survey-based study of the medicines-taking experience of patients with CAD treated at a secondary/tertiary care centre. All participants had been on SPM for ≥3 months. Results: In total, 696 eligible patients were sent the survey and 503 responded (72.3%). The median age was 70 years, and 403 (80.1%) were male; the median number of individual daily doses of all medicines was 6. The rate of non-adherence to at least one SPM was 43.5% (n=219), but 53.3% of reported non-adherence was to only one SPM. Statins contributed to 66.7% and aspirin to 61.7% of overall non-adherence identified by the Single Question (SQ) tool. In 30.8% of non-adherent patients (n=65), this was at least partly intentional. Barriers included forgetfulness (84.9%; n=186), worry that medicines will do more harm than good (33.8%; n=74), feeling hassled about medicines taking (18.7%; n=41), feeling worse when taking medicines (14.2%; n=31) and not being convinced of the benefit of medicines (9.1%; n=20). In a multivariate analysis, modifiable factors associated with overall non-adherence included being prescribed aspirin (OR: 2.22; 95% CI: 1.18 to 4.17), having specific concern about SPM (OR: 1.12; 95% CI: 1.07 to 1.18) and issues with repeat prescriptions (OR: 2.48; 95% CI: 1.26 to 4.90). Different factors were often associated with intentional versus unintentional non-adherence. Conclusions: Using appropriate self-report tools, patients share actual and potential modifiable barriers to adherence that can be addressed in clinical practice. Non-adherence behaviour was selective. Most non-adherence was driven by forgetfulness, concern about the harm caused by SPM and practical barriers.
  • Short phosphate glass fiber - PLLA composite to promote bone mineralization

    Melo, P.; Tarrant, E.; Swift, Thomas; Townshend, A.; German, M.; Ferreira, A-M.; Gentile, P.; Dalgarno, K. (Elsevier, 2019)
    The clinical application of composites seeks to exploit the mechanical and chemical properties of materials which make up the composite, and in researching polymer composites for biomedical applications the aim is usually to enhance the bioactivity of the polymer, while maintaining the mechanical properties. To that end, in this study medical grade Poly(L-lactic) acid (PLLA) has been reinforced with short phosphate-based glass fibers (PGF). The materials were initially mixed by melting PLLA granules with the short fibers, before being extruded to form a homogenous filament, which was pelletized and used as feedstock for compression moulding. As made the composite materials had a bending strength of 51 MPa ± 5, and over the course of eight weeks in PBS the average strength of the composite material was in the range 20–50 MPa. Human mesenchymal stromal cells were cultured on the surfaces of scaffolds, and the metabolic activity, alkaline phosphatase production and mineralization monitored over a three week period. The short fiber filler made no significant difference to cell proliferation or differentiation, but had a clear and immediate osteoinductive effect, promoting mineralization by cells at the material surface. It is concluded that the PLLA/PGF composite material offers a material with both the mechanical and biological properties for potential application to bone implants and fixation, particularly where an osteoinductive effect would be valuable.
  • Molecular insights on the interference of simplified lung surfactant models by gold nanoparticle pollutants

    Hossain, S.I.; Gandhi, N.S.; Hughes, Zak E.; Gu, Y.T.; Saha, S.C. (2019-08-01)
    Inhaled nanoparticles (NPs) are experienced by the first biological barrier inside the alveolus known as lung surfactant (LS), a surface tension reducing agent, consisting of phospholipids and proteins in the form of the monolayer at the air-water interface. The monolayer surface tension is continuously regulated by the alveolus compression and expansion and protects the alveoli from collapsing. Inhaled NPs can reach deep into the lungs and interfere with the biophysical properties of the lung components. The interaction mechanisms of bare gold nanoparticles (AuNPs) with the LS monolayer and the consequences of the interactions on lung function are not well understood. Coarse-grained molecular dynamics simulations were carried out to elucidate the interactions of AuNPs with simplified LS monolayers at the nanoscale. It was observed that the interactions of AuNPs and LS components deform the monolayer structure, change the biophysical properties of LS and create pores in the monolayer, which all interfere with the normal lungs function. The results also indicate that AuNP concentrations >0.1 mol% (of AuNPs/lipids) hinder the lowering of the LS surface tension, a prerequisite of the normal breathing process. Overall, these findings could help to identify the possible consequences of airborne NPs inhalation and their contribution to the potential development of various lung diseases.
  • Asymmetries between achromatic and chromatic extraction of 3D motion signals

    Kaestner, M.; Maloney, R.T.; Wailes-Newson, K.H.; Bloj, Marina; Harris, J.M.; Morland, A.B.; Wade, A.R. (2019-06)
    Motion in depth (MID) can be cued by high-resolution changes in binocular disparity over time (CD), and low-resolution interocular velocity differences (IOVD). Computational differences between these two mechanisms suggest that they may be implemented in visual pathways with different spatial and temporal resolutions. Here, we used fMRI to examine how achromatic and S-cone signals contribute to human MID perception. Both CD and IOVD stimuli evoked responses in a widespread network that included early visual areas, parts of the dorsal and ventral streams, and motion-selective area hMT+. Crucially, however, we measured an interaction between MID type and chromaticity. fMRI CD responses were largely driven by achromatic stimuli, but IOVD responses were better driven by isoluminant S-cone inputs. In our psychophysical experiments, when S-cone and achromatic stimuli were matched for perceived contrast, participants were equally sensitive to the MID in achromatic and S-cone IOVD stimuli. In comparison, they were relatively insensitive to S-cone CD. These findings provide evidence that MID mechanisms asymmetrically draw on information in precortical pathways. An early opponent motion signal optimally conveyed by the S-cone pathway may provide a substantial contribution to the IOVD mechanism.
  • Organometallic iridium arene compounds: the effects of C-donor ligands on anticancer activity

    Lord, Rianne M.; McGowan, P.C. (2019)
    In the past decade, libraries of iridium organometallic arene compounds have expanded rapidly, with the majority of their applications aimed towards effective catalysts and potential anti-cancer drug candidates. Researchers have begun to adapt the traditional “piano-stool” structures to include different bidentate ligands, ancillary ligands and extend the aromaticity and functionality of the arene substituent, all in the hope to optimize their activities and allow the determination of structure activity relationships. Many of the complexes incorporate N- and O-donor ligands, but more recently, these structures have been expanded to include C-donor ligands such as cyclometalated bidentate ligands and N-heterocyclic carbenes. This mini-review highlights the recent and ongoing research in C-donor iridium arene complexes, and discusses their importance as potential anticancer drugs.
  • Evaluating recruitment methods of patients with advanced cancer: a pragmatic opportunistic comparison

    Edwards, Zoe; Bennett, M.I.; Petty, Duncan R.; Blenkinsopp, Alison (2019)
    Background: Recruitment of patients with advanced cancer into studies is challenging. Objective: To evaluate recruitment methods in a study of pharmacist-led cancer pain medicines consultations and produce recommendations for future studies. Method: Two methods of recruitment were employed: 1) community-based (general practitioner computer search, identification by general practitioner, community pharmacist or district nurse and hospital outpatient list search), and 2) hospice-based (in and outpatient list search). Patients identified in method 1 were invited by post and in method 2 were invited face-to-face. Information was designed in collaboration with patients and carers. Results: 128 patients were identified (85 from the community and 43 from the hospice), 47 met the inclusion criteria. Twenty-three agreed to take part and 19 completed the study, 17 of whom were already under specialist palliative care. Recruitment rates were 7% for community-based methods and 40% for hospice. The recruitment methods differed in intensity of resource use. Recruitment via letter and a lack of engagement by healthcare professionals were found to be barriers. Facilitators included the researcher having personal involvement in recruitment. Conclusion: The overall recruitment rate was in line with other studies for this patient cohort. Attempts to identify and engage patients through community-based postal contact were less effective than where personal contact with patients was both possible and occurred. Methods were less successful at recruiting patients who were not already engaged with hospice services.
  • Inactivation of apaziquone by haematuria: implications for the design of phase III clinical trials against non-muscle invasive bladder cancer

    Phillips, Roger M.; Loadman, Paul M.; Reddy, G. (2019-06)
    Purpose: Despite positive responses in phase II clinical trials, the bioreductive prodrug apaziquone failed to achieve statistically significant activity in non-muscle invasive bladder cancer in phase III trials. Apaziquone was administered shortly after transurethral resection and here we test the hypothesis that haematuria inactivates apaziquone. Methods: HPLC analysis was used to determine the ability of human whole blood to metabolise apaziquone ex vivo. An in vitro model of haematuria was developed and the response of RT112 and EJ138 cells following a 1-h exposure to apaziquone was determined in the presence of urine plus or minus whole blood or lysed whole blood. Results: HPLC analysis demonstrated that apaziquone is metabolised by human whole blood with a half-life of 78.6±23.0 min. As a model for haematuria, incubation of cells in media containing up to 75% buffered (pH 7.4) urine and 25% whole blood was not toxic to cells for a 1-h exposure period. Whole blood (5% v/v) significantly (p<0.01) reduced the potency of apaziquone in this experimental model. Lysed whole blood also significantly (p<0.05) reduced cell growth, although higher concentrations were required to achieve an effect (15% v/v). Conclusions: The results of this study demonstrate that haematuria can reduce the potency of apaziquone in this experimental model. These findings impact upon the design of further phase III clinical trials and strongly suggest that apaziquone should not be administered immediately after transurethral resection of non-muscle invasive bladder cancer when haematuria is common.
  • Excavations at Old Scatness, Shetland. Volume 3: The Post-medieval township

    Dockrill, Stephen J.; Bond, Julie M.; Turner, V.E.; Brown, L.D.; Bashford, D.J.; Cussans, Julia E.; Nicholson, R.A. (Shetland Heritage Publications, 2019)
  • Perceived time is spatial frequency dependent

    Aaen-Stockdale, Craig; Hotchkiss, John; Heron, James; Whitaker, David J. (2011-06-01)
    We investigated whether changes in low-level image characteristics, in this case spatial frequency, were capable of generating a well-known expansion in the perceived duration of an infrequent “oddball” stimulus relative to a repeatedly-presented “standard” stimulus. Our standard and oddball stimuli were Gabor patches that differed from each other in spatial frequency by two octaves. All stimuli were equated for visibility. Rather than the expected “subjective time expansion” found in previous studies, we obtained an equal and opposite expansion or contraction of perceived time dependent upon the spatial frequency relationship of the standard and oddball stimulus. Subsequent experiments using equi-visible stimuli reveal that mid-range spatial frequencies (ca. 2 c/deg) are consistently perceived as having longer durations than low (0.5 c/deg) or high (8 c/deg) spatial frequencies, despite having the same physical duration. Rather than forming a fixed proportion of baseline duration, this bias is constant in additive terms and implicates systematic variations in visual persistence across spatial frequency. Our results have implications for the widely cited finding that auditory stimuli are judged to be longer in duration than visual stimuli.
  • The MK2 cascade regulates mGluR-dependent synaptic plasticity and reversal learning

    Privitera, Lucia; Hogg, Ellen L.; Gaestel, M.; Wall, M.J.; Corrêa, Sonia A.L. (2019-09-01)
    The ability to either erase or update the memories of a previously learned spatial task is an essential process that is required to modify behaviour in a changing environment. Current evidence suggests that the neural representation of such cognitive flexibility involves the balancing of synaptic potentiation (acquisition of memories) with synaptic depression (modulation and updating previously acquired memories). Here we demonstrate that the p38 MAPK/MAPK-activated protein kinase 2 (MK2) cascade is required to maintain the precise tuning of long-term potentiation and long-term depression at CA1 synapses of the hippocampus which is correlated with efficient reversal learning. Using the MK2 knockout (KO) mouse, we show that mGluR-LTD, but not NMDAR-LTD, is markedly impaired in mice aged between 4 and 5 weeks (juvenile) to 7 months (mature adult). Although the amplitude of LTP was the same as in wildtype mice, priming of LTP by the activation of group I metabotropic receptors was impaired in MK2 KO mice. Consistent with unaltered LTP amplitude and compromised mGluR-LTD, MK2 KO mice had intact spatial learning when performing the Barnes maze task, but showed specific deficits in selecting the most efficient combination of search strategies to perform the task reversal. Findings from this study suggest that the mGluR-p38-MK2 cascade is important for cognitive flexibility by regulating LTD amplitude and the priming of LTP.
  • A bridge too far: is a degree the right path?

    Binns, Carole L. (2019-03-07)
    Studies of graduate destinations generally report positive outcomes for working-class graduates, particularly professionally validated programmes such as pharmacy or social work, which offer specific career pathways. However, I know of working-class graduates with good degrees from good institutions who are in relatively menial positions in the leisure and retail sector. It is as if such students are unable to move beyond working-class jobs and embrace the middle-class careers that a degree should unlock.
  • Effect before cause: supramodal recalibration of sensorimotor timing

    Heron, James; Hanson, James Vincent Michael; Whitaker, David J. (2009)
    Our motor actions normally generate sensory events, but how do we know which events were self generated and which have external causes? Here we use temporal adaptation to investigate the processing stage and generality of our sensorimotor timing estimates. Methodology/Principal Findings: Adaptation to artificially-induced delays between action and event can produce a startling percept¿upon removal of the delay it feels as if the sensory event precedes its causative action. This temporal recalibration of action and event occurs in a quantitatively similar manner across the sensory modalities. Critically, it is robust to the replacement of one sense during the adaptation phase with another sense during the test judgment. Conclusions/Significance: Our findings suggest a high-level, supramodal recalibration mechanism. The effects are well described by a simple model which attempts to preserve the expected synchrony between action and event, but only when causality indicates it is reasonable to do so. We further demonstrate that this model successfully characterises related adaptation data from outside the sensorimotor domain.
  • A matter of months: High precision migration chronology of a Bronze Age female

    Frei, K.M.; Villa, C.; Jorkov, M.L.; Allentoft, M.E.; Kaul, F.; Ethelberg, P.; Reiter, S.S.; Wilson, Andrew S.; Taube, M.; Olsen, J.; Lynnerup, N.; Willerslev, E.; Kristiansen, K.; Frei, R. (2017-06-05)
    Establishing the age at which prehistoric individuals move away from their childhood residential location holds crucial information about the socio dynamics and mobility patterns in ancient societies. We present a novel combination of strontium isotope analyses performed on the over 3000 year old “Skrydstrup Woman” from Denmark, for whom we compiled a highly detailed month-scale model of her migration timeline. When combined with physical anthropological analyses this timeline can be related to the chronological age at which the residential location changed. We conducted a series of high-resolution strontium isotope analyses of hard and soft human tissues and combined these with anthropological investigations including CT-scanning and 3D visualizations. The Skrydstrup Woman lived during a pan-European period characterized by technical innovation and great social transformations stimulated by long-distance connections; consequently she represents an important part of both Danish and European prehistory. Our multidisciplinary study involves complementary biochemical, biomolecular and microscopy analyses of her scalp hair. Our results reveal that the Skrydstrup Woman was between 17–18 years old when she died, and that she moved from her place of origin -outside present day Denmark- to the Skrydstrup area in Denmark 47 to 42 months before she died. Hence, she was between 13 to 14 years old when she migrated to and resided in the area around Skrydstrup for the rest of her life. From an archaeological standpoint, this one-time and one-way movement of an elite female during the possible “age of marriageability” might suggest that she migrated with the aim of establishing an alliance between chiefdoms. Consequently, this detailed multidisciplinary investigation provides a novel tool to reconstruct high resolution chronology of individual mobility with the perspective of studying complex patterns of social and economic interaction in prehistory.
  • From Macro to Micro: Multi-scalar Digital Approaches at the Sculptor’s Cave, North-East Scotland

    Büster, Lindsey; Armit, Ian; Evans, Adrian A.; Sparrow, Thomas; Kershaw, Rachael; Wilson, Andrew S. (2019-02-08)
    Excavations in the 1920s and 1970s at the Sculptor’s Cave, North-East Scotland, revealed that the site was used for mortuary rituals during the Late Bronze Age (c. 1100–800 BC) and Roman Iron Age (late first to fourth centuries AD), whilst a series of Pictish symbols carved into its entrance walls suggest that the cave’s importance continued into the Early Medieval Period. A new programme of analysis has utilised advanced 3D digital documentation and 3D metrology (specifically, 3D laser scanning) to enable this inaccessible site to be appreciated by wider audiences and analysed remotely. Detailed in situ recording of the Pictish symbols was undertaken using macro-level structured light scanning and the high-fidelity digital models blended with terrestrial laser scan data of the cave interior to show the location and detail of the carvings. This chapter examines the value of emerging digital approaches in the analysis, presentation and management of the Sculptor’s Cave, from the elucidation of additional carved details and the monitoring of surface degradation, to the dissemination of this difficult-to-access site to the wider public via online platforms.
  • Interactions of a zwitterionic thiophene-based conjugated polymer with surfactants

    Costa, T.; de Azevedo, D.; Stewart, Beverly; Knaapila, M.; Valente, A.J.M.; Kraft, M.; Scherf, U.; Burrows, H.D. (2015-12-15)
    In this paper we investigate the optical and structural properties of a zwitterionic poly[3-(N-(4-sulfonato-1-butyl)-N,N-diethylammonium)hexyl-2,5-thiophene] (P3SBDEAHT) conjugated polyelectrolyte (CPE) and its interaction in water with surfactants, using absorption, photoluminescence (PL), electrical conductivity, molecular dynamics simulations (MDS) and small-angle X-ray scattering (SAXS). Different surfactants were studied to evaluate the effect of the head group and chain length on the self-assembly. PL data emphasize the importance of polymer–surfactant electrostatic interactions in the formation of complexes. Nevertheless, conductivity and MDS data have shown that nonspecific interactions also play an important role. These seem to be responsible for the spatial position of the surfactant tail in the complex and, eventually, for breaking-up P3SBDEAHT aggregates. SAXS measurements on P3SBDEAHT-zwitterionic cocamidopropyl betaine (CAPB) surfactant complexes showed a specific structural organization of the system. The CAPB surfactant promotes a structural transition from pure P3SBDEAHT 3-dimensional aggregates (radius of gyration ∼85 Å) to thick cylindrical aggregates (∼20 Å) where all CAPB molecules are associated with the polymer. For molar ratios (in terms of the polymer repeat unit) >1 the SAXS interference maximum of the complexes resembles that of pure CAPB thus suggesting ongoing phase segregation in the formation of a “pure” CAPB phase.
  • Incorporation of a Cationic Conjugated Polyelectrolyte CPE within an Aqueous Poly(vinyl alcohol) Sol

    Knaapila, M.; Stewart, Beverly; Costa, T.; Rogers, S.E.; Pragana, J.; Fonseca, S.M.; Valente, A.J.M.; Ramos, M.L.; Murtinho, D.; Costa Pereira, J.; Mallavia, R.; Burrows, H.D. (2016-11-16)
    We report on a multiscale polymer-within-polymer structure of the cationic conjugated polyelectrolyte poly{[9,9-bis(6′-N,N,N-trimethylammonium)hexyl]fluorene–phenylene} (HTMA-PFP) in aqueous poly(vinyl alcohol) (PVA) sol. Molecular dynamics simulations and small-angle neutron scattering (SANS) data show that HTMA-PFP forms aggregates in water but becomes entangled by PVA (with a 1:1 molar ratio of HTMA-PFP to PVA) and eventually immersed in PVA clusters (with the ratio 1:4). This is attributed to the hydrophobic–hydrophilic balance. Contrast variation data with regular and deuterated PVA support a rigid body model, where HTMA-PFP is confined as locally isolated, but closely located, chains within PVA clusters, which alter correlation distances within the system. These results are supported by enhanced photoluminescence (PL) and ionic conductivity which, together with a red-shift in UV/vis absorption spectra, indicate the breakup of HTMA-PFP aggregates upon PVA addition.
  • Multiple spatial frequency channels in human visual perceptual memory

    Nemes, Vanda A.; Whitaker, David J.; Heron, James; McKeefry, Declan J. (2011-12-08)
    Current models of short-term visual perceptual memory invoke mechanisms that are closely allied to low-level perceptual discrimination mechanisms. The purpose of this study was to investigate the extent to which human visual perceptual memory for spatial frequency is based upon multiple, spatially tuned channels similar to those found in the earliest stages of visual processing. To this end we measured how performance on a delayed spatial frequency discrimination paradigm was affected by the introduction of interfering or ‘memory masking’ stimuli of variable spatial frequency during the delay period. Masking stimuli were shown to induce shifts in the points of subjective equality (PSE) when their spatial frequencies were within a bandwidth of 1.2 octaves of the reference spatial frequency. When mask spatial frequencies differed by more than this value, there was no change in the PSE from baseline levels. This selective pattern of masking was observed for different spatial frequencies and demonstrates the existence of multiple, spatially tuned mechanisms in visual perceptual memory. Memory masking effects were also found to occur for horizontal separations of up to 6 deg between the masking and test stimuli and lacked any orientation selectivity. These findings add further support to the view that low-level sensory processing mechanisms form the basis for the retention of spatial frequency information in perceptual memory. However, the broad range of transfer of memory masking effects across spatial location and other dimensions indicates more long range, long duration interactions between spatial frequency channels that are likely to rely contributions from neural processes located in higher visual areas.
  • Adaptation reveals multi-stage coding of visual duration

    Heron, James; Fulcher, Corinne; Collins, Howard; Whitaker, David J.; Roach, N.W. (2019-02-28)
    In conflict with historically dominant models of time perception, recent evidence suggests that the encoding of our environment’s temporal properties may not require a separate class of neurons whose raison d'être is the dedicated processing of temporal information. If true, it follows that temporal processing should be imbued with the known selectivity found within non-temporal neurons. In the current study, we tested this hypothesis for the processing of a poorly understood stimulus parameter: visual event duration. We used sensory adaptation techniques to generate duration aftereffects: bidirectional distortions of perceived duration. Presenting adapting and test durations to the same vs different eyes utilises the visual system’s anatomical progression from monocular, pre-cortical neurons to their binocular, cortical counterparts. Duration aftereffects exhibited robust inter-ocular transfer alongside a small but significant contribution from monocular mechanisms. We then used novel stimuli which provided duration information that was invisible to monocular neurons. These stimuli generated robust duration aftereffects which showed partial selectivity for adapt-test changes in retinal disparity. Our findings reveal distinct duration encoding mechanisms at monocular, depth-selective and depthinvariant stages of the visual hierarchy.
  • ‘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.; Knüsel, C.J.; Wilson, Andrew S.; Chapoulie, R. (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.

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