Publications by authors named "Ian D McCarthy"

Objective: Visual processing deficits arising in dementia are associated with particular functional disability. This study aimed to investigate the effects of the built environment on mobility and navigation in people with dementia-related visual loss.

Methods: Participants with posterior cortical atrophy (PCA; "visual-variant Alzheimer's"; n = 11), typical Alzheimer's disease (tAD; N = 10), and controls (n = 13) repeatedly walked down routes within a simplified real-world setting.

View Article and Find Full Text PDF

European sea bass (Dicentrarchus labrax) is a species of high commercial and recreational value, but it exhibits highly variable recruitment rates and has been subject to recent declines. Emergency management measures put in place to protect spawning stocks include the annual closure of commercial and recreational fisheries over a 2-month, February-March, window. Whether this protection measure is having the desired outcome for this data-poor species remains unclear.

View Article and Find Full Text PDF

The study of geometric morphometrics among stocks has proven to be a valuable tool in delineating fish spatial distributions and discriminating distinct population units. Variations in fish body morphology can be linked to genetic factors or to phenotypic adaptability in response to environmental variables. The tub gurnard () is a demersal species that usually lives in the bottom of the continental shelf, being widely distributed along the northeast Atlantic, Mediterranean and Black seas.

View Article and Find Full Text PDF

Introduction: Visual processing deficits in Alzheimer's disease are associated with diminished functional independence. While environmental adaptations have been proposed to promote independence, recent guidance gives limited consideration to such deficits and offers conflicting recommendations for people with dementia. We evaluated the effects of clutter and color contrasts on performances of everyday actions in posterior cortical atrophy and memory-led typical Alzheimer's disease.

View Article and Find Full Text PDF

Introduction: Clinical reports describe patients with Alzheimer's disease (AD) exhibiting atypical adaptive walking responses to the visual environment; however, there is limited empirical investigation of such behaviors or factors modulating their expression. We aim to evaluate effects of lighting-based interventions and clinical presentation (visual- vs memory-led) on walking function in participants with posterior cortical atrophy (PCA) and typical AD (tAD).

Methods: Participants with PCA (n = 10), tAD (n = 9), and healthy controls (n = 12) walked to visible target destinations under different lighting conditions within two pilot repeated-measures design investigations (Experiment 1: 32 trials per participant; Experiment 2: 36 trials per participant).

View Article and Find Full Text PDF

The impacts of ocean acidification remain less well-studied in starfish compared to other echinoderm groups. This study examined the combined effects of elevated pCO and arm regeneration on the performance of the intertidal predatory starfish Asterias rubens, as both are predicted to come at a cost to the individual. A two-way factorial experiment (~400 μatm vs ~1000 μatm; autotomised vs non-automised individuals) was used to examine growth rates, lipid content (pyloric caeca and gonads), and calcium content (body wall) in both intact and regenerating arms, as well as subsequent effects on rate of arm regeneration, righting time (behaviour) and mortality over 120 days.

View Article and Find Full Text PDF

Impacts of the interactive effects of ocean acidification (OA) with other anthropogenic environmental stressors on marine biodiversity are receiving increasing attention in recent years. However, little is known about how organismal responses to OA may be influenced by common phenomena such as autotomy and sexual dimorphism. This study evaluated the long-term (120 days) combined effects of OA (pH 7.

View Article and Find Full Text PDF

The whitemouth croaker (Micropogonias furnieri) is one of the most commercially important species along the Atlantic coast of South America. Moreover, some of its biological traits (long life span, inshore feeding, high trophic position) make this species a suitable sentinel of coastal pollution. Here, we investigated contamination by multiple legacy and emerging organic pollutants, such as brominated and chlorinated flame retardants, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in whitemouth croakers from two estuaries (Guanabara and Sepetiba Bays) located in industrialized and urbanized areas in Rio de Janeiro State, Southeastern Brazil.

View Article and Find Full Text PDF

The expression of individual behaviour as a function of environmental variation (behavioural plasticity) is recognized as a means for animals to modify their phenotypes in response to changing conditions. Plasticity has been studied extensively in recent years, leading to an accumulation of evidence for behavioural plasticity within natural populations. Despite the recent attention given to studying individual variation in behavioural plasticity, there is still a lack of consensus regarding its causes and constraints.

View Article and Find Full Text PDF

Marine crabs inhabit shallow coastal/estuarine habitats particularly sensitive to climate change, and yet we know very little about the diversity of their responses to environmental change. We report the effects of a rarely studied, but increasingly prevalent, combination of environmental factors, that of near-future pCO (~1000 µatm) and a physiologically relevant 20% reduction in salinity. We focused on two crab species with differing abilities to cope with natural salinity change, and revealed via physiological and molecular studies that salinity had an overriding effect on ion exchange in the osmoregulating shore crab, Carcinus maenas.

View Article and Find Full Text PDF
Article Synopsis
  • Multiple human-induced stressors, like ocean acidification and shading from infrastructure, can significantly affect marine organisms, particularly in coastal areas.
  • A study on hermit crabs exposed to reduced pH and darkness revealed that both stressors increased mortality, while growth was negatively influenced by the combination of stressors.
  • Interestingly, while crabs maintained calcification levels despite lower pH, shading affected their behavior towards predator and resource signals, highlighting the complex interaction between local disturbances and global environmental changes.
View Article and Find Full Text PDF

Objective: Deficits in spatial navigation are characteristic and disabling features of typical Alzheimer's disease (tAD) and posterior cortical atrophy (PCA). Visual cues have been proposed to mitigate such deficits; however, there is currently little empirical evidence for their use.

Methods: The effect of visual cues on visually guided navigation was assessed within a simplified real-world setting in individuals with tAD ( = 10), PCA ( = 8), and healthy controls ( = 12).

View Article and Find Full Text PDF

Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g.

View Article and Find Full Text PDF

Consistent individual differences in animal performance drive individual fitness under variable environmental conditions and provide the framework through which natural selection can operate. Underlying this concept is the assumption that individuals will display consistent levels of performance in fitness-related traits and interest has focused on individual variation and broad sense repeatability in a range of behavioural and physiological traits. Despite playing a central role in maintenance and growth, and with considerable inter-individual variation documented, broad sense repeatability in rates of protein synthesis has not been assessed.

View Article and Find Full Text PDF

The flooding dose technique of Garlick et al. (1980) has become the main method for measuring tissue and whole-animal rates of protein synthesis in ectotherms. However, single tissue samples are used to determine rates of protein synthesis and no studies have examined the pattern of flooding in large tissues such as the white muscle in fishes, which can comprise up to 55% of the wet body mass of a fish and which is poorly perfused.

View Article and Find Full Text PDF

For the first time, use of the flooding dose technique using (3)H-Phenylalanine is validated for measuring whole-animal and tissue-specific rates of protein synthesis in the blue mussel Mytilus edulis (61mm shell length; 4.0g fresh body mass). Following injection, the phenylalanine-specific radioactivities in the gill, mantle and whole-animal free pools were elevated within one hour and remained elevated and stable for up to 6h following injection of (3)H-phenylalanine into the posterior adductor muscle.

View Article and Find Full Text PDF

Bioindicators are species for which some quantifiable aspect of its biology, a biomarker, is assumed to be sensitive to ecosystem health. However, there is frequently a lack of information on the underlying genetic and environmental drivers shaping the spatiotemporal variance in prevalence of the biomarkers employed. Here, we explore the relative role of potential variables influencing the spatiotemporal prevalence of biomarkers in dab, Limanda limanda, a species used as a bioindicator of marine contaminants.

View Article and Find Full Text PDF

In order for natural selection to operate, physiological and behavioural traits must exhibit both inter-individual variability and intra-individual consistency (i.e. repeatability) in performance.

View Article and Find Full Text PDF

With the use of lasers for ablation purposes in spinal surgery, the tissue temperature increases above the boiling point of water, leading to tissue ablation by vaporisation. Due to the thermal environment engendered by the use of lasers, there is concern about the safety of the surrounding important structures, such as dura mater, dorsal root ganglia, and nerve roots.

View Article and Find Full Text PDF

Protein synthesis is one of the major energy-consuming processes in all living organisms. Post-prandial changes in protein synthesis have been studied in a range of animal taxa but have been little studied in fish larvae. Using the flooding-dose method, we measured post-prandial changes in whole-body rates of protein synthesis in regularly fed red drum Sciaenops ocellatus (Linnaeus) larvae for 24-28 h following their daily meal.

View Article and Find Full Text PDF

Stable isotopes (delta(15)N and delta(13)C) are being widely applied in ecological research but there has been a call for ecologists to determine species- and tissue-specific diet discrimination factors ((13)C and (15)N) for their study animals. For large sharks stable isotopes may provide an important tool to elucidate aspects of their ecological roles in marine systems, but laboratory based controlled feeding experiments are impractical. By utilizing commercial aquaria, we estimated (15)N and (13)C of muscle, liver, vertebral cartilage and a number of organs of three large sand tiger (Carcharias taurus) and one large lemon shark (Negaprion brevirostris) under a controlled feeding regime.

View Article and Find Full Text PDF

The European flounder (Platichthys flesus L.) is used in ecotoxicological studies to provide detailed information on the effects of pollution on individual fish. Data on population and evolutionary level effects are, however, limited.

View Article and Find Full Text PDF

Dab (Limanda limanda) are the principal target fish species in offshore biomonitoring programmes in the UK; however, detailed knowledge of genetic structure and connectivity among sampling locations is unavailable. Here, the isolation and characterization of 30 polymorphic microsatellite loci for dab is described. The number of alleles per locus ranged from 2 to 42, with observed heterozygosities ranging from 0.

View Article and Find Full Text PDF

Contaminant exposure can affect development, growth, and behaviour of fish larvae, but its effect on rates of protein synthesis and protein degradation are not known. The aim of the present study was to examine the effects of a single pulsed dose aqueous exposure to environmentally realistic levels of two contaminants, atrazine (0, 40 and 80 microgl(-1)) and malathion (0, 1 and 10 microgl(-1)), on growth and protein synthesis in red drum (Sciaenops ocellatus) larvae. Growth was assessed in terms of increase in length, weight, and protein content over an 8-day period following exposure.

View Article and Find Full Text PDF

Iodixanol (IDX) is a water soluble opacifier widely used in radiographical examinations of blood vessels and neural tissue, and it has been suggested as a potential contrast media in acrylic bone cement. The effect of the iodixanol particle size on the polymerisation process of the bone cement, the molecular weight, and the quasi-static mechanical properties have been investigated in this article. The investigation was performed using radiolucent Palacos powder mixed with 8 wt% of iodixanol with particle sizes ranging from 3 to 20 microm MMD, compared with commercial Palacos R (15 wt% ZrO2) as control.

View Article and Find Full Text PDF