Richard A. Armstrong

Aston University · Department of Optometry

Methane (CH4) is common in the atmosphere of Earth and largely results from biological activity. Hence, the detection of the possible presence of CH4 on Mars is critical to establishing the presence of current microbial life on the surface. The attempts to detect CH4 in the Martian atmosphere over the last 50 years are therefore critically reviewed...

Unusual horizontal protrusions were photographed on rocks in Gale crater, Mars by the Curiosity rover 'Mastcam' and 'ChemCam' between sol 3786 and 3800. These protrusions follow horizons of bedding in the sedimentary rocks and have a variety of morphologies including 'spike-like', blunt 'wedge-like', 'plate-like', or 'serrated' protrusions. These f...

The objective of this study was to identify those variables associated with either the whole lichen thallus (size of thallus, number and density of lobes, degree of lobe crowding) or with individual lobes (mean and variation in the degree of connection between lobes, mean and variation in lobe width) which determine annual radial growth rate (RaGR)...

White and dark gray oblong-ovoid cocoon-egg-like forms (“cocoon-eggs”), less than a mm in diameter, many with a single hole in one end, and some with unidentifiable specimens protruding from (exiting or entering) these holes, were photographed on mudstone in Gale Crater, Mars, on Sol 1302. If biological some of these cocoon-eggs may be frozen, foss...

The relationship of macular pigments and foveal anatomy to the perception of Maxwell’s spot (MS) and Haidinger’s brushes (HB) entoptic phenomena were investigated. Dual-wavelength-autofluorescence and OCT were used to define macular pigment density and foveal anatomy in 52 eyes. MS was generated by alternating unpolarized red/blue and red/green uni...

An array of formations resembling the fossilized remains of Ediacaran and Cambrian fauna and other organisms have been observed embedded atop sediments in the dried lake beds of Gale Crater, Mars. Specimens similar in morphology have been found together, or upon adjacent and nearby rocks and mudstone.These include forms morphologically similar to p...

An unusual specimen referred to as 'Grange' was photographed on Mars by the Curiosity rover on Sol 2217 close to the 'Inverness' drilling site at Gale crater. 'Grange' appears to be composed of a crystalline/carbonate resembling calcite and extends from a fissure onto the rock surface as a partially eroded oval object approximately 20 mm in diamete...

Argyrophilic grain disease (AGD), a heterogenous late-onset tauopathy, is often associated with co-pathologies such as Alzheimer’s disease neuropathologic change (ADNC) and transactive response (TAR) DNA-binding protein 43 (TDP-43). To investigate heterogeneity among AGD cases, we studied the tau-immunoreactive neurofibrillary tangles (NFT), pre-ta...

Several brain regions and fiber tracts have been implicated in the pathology which may be caused by substance use. This chapter provides an overview of the structure and functions of these regions including: (1) areas of cerebral cortex such as the prefrontal cortex (PFC) and cingulate gyrus (CG), (2) major fiber tracts such as the corpus callosum...

Rocks with numerous deep concave holes similar to trace fossils fashioned by mollusks have been photographed by Viking 2 in Utopia Planitia and the rover Perseverance in the ancient lakes beds of Jezero Crater, Mars. Specimens resembling colonies of worm-like burrowing mollusks occupy some of these concave cavities. A morphological quantitative ana...

Pattern analysis describes a series of statistical methods to determine whether a variable shows significant changes in space or time and with applications in many scientific fields. Large numbers of photographs of the Martian landscape, including surface details of rock, boulders, and soil have been obtained by the ‘Spirit’, ‘Opportunity’, and ‘Cu...

Mars has been subject to repeated waxing and waning episodes of extreme chaotic obliquity (axial tilting) for at least four billion years. Obliquity is currently at 25.19 degrees and has exceeded 80◦. Each time obliquity exceeds 40◦ Martian atmospheric pressures and global temperatures increase causing the melting of glaciers and permafrost and sub...

Forms resembling sponges or coral were photographed in Gale crater, Mars by the Curiosity rover 'Mars Hand Lens Imager' (MAHLI) on sol 3396 that may represent the result of either mineralization or be evidence of fossilisation. At least seven individual structures were observed showing various degrees of fragmentation, but the most complete specime...

The quantitative analysis of plant growth ('plant growth analysis', PGA) has been particularly valuable in investigations of the development of higher plants and the influence of environmental factors on growth. This review describes various aspects of a PGA modified for application specifically to lichens and is illustrated with special reference...

Symmetrical micro-structures from 1-2 mm to 1 cm in diameter with multiple appendages and shapes resembling "spiders" have been photographed in Gale Crater, many attached to honeycombed or multi-layered sediments similar to dolomite and archean stromatolites of Earth dated to over 2.2bya. Oval-shaped mm-in-size lifelike specimens with forward-facin...

Purpose: To determine whether UK optometrists and ophthalmologists provide target refraction advice to patients prior to cataract surgery, and when this should first be discussed. Methods: Optometrists and ophthalmologists were asked to complete a survey of two clinical vignettes (both older patients with cataract; a pre-operative myope who rout...

Fungal reproductive behavior, the growth of hyphae and mycelium, and the production of spores, on Earth and Mars, are reviewed. Spherical specimens that nearly 70 experts have identified as fungal "puffballs" ("basidiomycota") have been photographed in the equatorial regions of Mars, within Meridiani Planum in particular. Over two dozen "puffballs"...

A proportion of patients with motor neuron disease (MND) exhibit the clinical signs and symptoms of frontotemporal dementia (FTD) while some patients with FTD also develop the clinical features of MND. Moreover, frontotemporal lobar degeneration (FTLD), the pathological substrate of FTD, may share with MND the common feature of a pathology affectin...

In the ancient and recent past, various niches on Mars were habitable and possibly inhabited by organisms that have evolved and adapted to extreme surface and subsurface environments. Habitability is promoted by the high levels of iron that promotes melanization of various organisms that protects against radiation. Glacial and water-ice below the s...

Lichens successfully occur on Earth in a variety of ‘extreme' habitats including hot and cold deserts and in the Arctic, Antarctic and Alpine regions and are frequently the earliest ‘pioneer' organisms to colonize rock and soil. Hence, once the initial problems of lack of an intrinsic global magnetic field and low surface temperatures have been sol...

Statistical comparisons were made between various ‘tube-like’ structures photographed on Mars by Curiosity and Opportunity rovers in Gale and Endurance craters respectively and the worm ‘cases’ of terrestrial tube worms. Various statistical analyses, including principal components analysis (PCA) based on various metrics, suggested considerable simi...

Post-hoc tests are frequently used to make unplanned comparisons among group means after analysis of variance (ANOVA). This article surveys current practice in the use of post-hoc tests in articles published in Clinical and Experimental Optometry (CXO), Ophthalmic and Physiological optics (OPO), and Optometry and Vision Science (OVS), and provides...

In this book we present over 800 photographs that as a collective totality conclusively proves there is life on Mars. These include photos of Martian tube worms, "crab-like" organisms, algae, microbial mats, stromatolites, lichens, fungi, fungus, fossils; and sequential images documenting that Martian organisms are growing out of the ground, increa...

Purpose: The purpose of this study was to determine if a battery of polarization-modulated stimuli, quantified as a single metric, is effective in identifying macular disease in the presence/absence of cataract or pseudophakia. Methods: Using a modified liquid crystal display, polarization pattern perception (PPP) for a formulated battery of geo...

We present over 200 photographs that as a collective totality proves there is life on Mars. These include photos of Martian algae, microbial mats, stromatolites, lichens, fungi, fungus, fossils, tubular organisms; and sequential images documenting that Martian organisms are growing out of the ground, increasing in size, moving to new locations; and...

Statistical comparisons were made between the populations of Martian spheroids photographed by Opportunity and terrestrial Moqui balls and between the stalked Martian spheroids and reproductive podetia of the lichen Dibaeis baeomyces. Principal components analysis (PCA)based on various metrics suggested significant differences in statistical proper...

Objectives: As reported previously, tear film surface quality (TFSQ) should be considered in contact lens (CL) fitting. This study followed noninvasive keratograph tear film break-up time (NIKBUT) in CL wearers for 12 months to validate its clinical utility in predicting CL performance. Methods: Fifty-five subjects (M/F=17/38) aged 26±4 years we...

Fungi thrive in radiation intense environments. Sequential photos document that fungus-like Martian specimens emerge from the soil and increase in size, including those resembling puffballs (Basidiomycota). After obliteration of spherical specimens by the rover wheels, new sphericals--some with stalks--appeared atop the crests of old tracks. Sequen...

The search for life on Mars is one of the main objectives of space missions. At “Pahrump Hills Field Site” (Gale Crater, Mojave target), inside the mudstones of the Murray lacustrine sequence, Curiosity rover found organic materials and lozenge shaped laths considered by NASA as pseudomorphic crystals. Besides it detected mineral assemblages sugges...

The human brain develops from a layer of ectoderm located on the surface of the developing embryo. Invagination of this layer of cells ultimately forms a neural tube, which becomes differentiated into forebrain, midbrain, and hindbrain. This chapter provides a basic guide to the structure and function of the brain based on six key histological sect...

Numerous massive black and complex araneiforms with features categorized as "trees" "rivers" and dendritic radial "spiders" and ranging from a few meters to over 300 meters in size, appear on the surface of the upper northern and lower southern hemispheres of Mars, during the Spring, paralleling the melting of the polar ice-caps which consist of co...

The dried lake beds of Gale Crater have been identified by NASA's rover crews as a likely source of fossils. Formations resembling fossilized stromatolites, algae, acritarchs and metazoans have been previously observed and reported in peer reviewed scientific periodicals. A detailed search of NASA's Gale Crater image-data-base was conducted with a...

Purpose: Determine the repeatability of and optimum stimulus parameters for testing polarization pattern perception in a real-world clinical population, and assess the ability of polarization perception to distinguish normal from abnormal eyes. Methods: Polarization perception was evaluated in staff and patients attending ophthalmology clinics a...

Billions of years ago, the Northern Hemisphere of Mars may have been covered by at least one ocean and thousands of lakes and rivers. These findings, based initially on telescopic observations and images by the Mariner and Viking missions, led investigators to hypothesize that stromatolite fashioning cyanobacteria may have proliferated in the surfa...

A hypothesis is proposed to explain the pathogenesis of neurodegenerative disease and the diversity of its phenotypes. The hypothesis is based on seven main propositions: 1) neurodegenerative disease is associated with multiple risk factors, 2) age is the most important of the risk factors, 3) aging differentially affects neuroanatomical pathways,...

Thalli of the crustose lichen Ochrolechia parella have marginal ‘growth rings’ enabling rapid estimation of radial growth rates (RaGR) over successive years. I obtained a growth curve, viz. changes in RaGR with thallus size, from rings of two populations of O. parella and in one population, and compared the growth curves obtained from rings and by...

Throughout its mission at Eagle Crater, Meridiani Planum, the rover Opportunity photographed thousands of mushroom-lichen-like formations with thin stalks and spherical caps, clustered together in colonies attached to and jutting outward from the tops and sides of rocks. Those on top-sides were often collectively oriented, via their caps and stalks...

Gale Crater was an ancient Martian lake that has periodically filled with water and which may still provide a watery environment conducive to the proliferation and fossilization of a wide range of organisms, especially algae. To test this hypothesis and to survey the Martian landscape, over 3,000 photographs from NASA's rover Curiosity Gale Crater...

Alzheimer's disease neuropathologic change (ADNC) in the form of β-amyloid (Aβ) deposits occurs not only in Alzheimer's disease (AD) and Down's syndrome (DS) but also as a 'co-pathology' in several disorders including dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and chronic traumatic encephalopathy (CTE). To determine whether c...

Two major pathological changes can be observed in the brain of cases of Alzheimer’s disease (AD): (1) the deposition of beta-amyloid (Abeta) as discrete deposits and (2) the formation of intracellular neurofibrillary tangles (NFT). Data on the relative abundances of these pathologies are routinely used both in the pathological diagnosis of AD and i...

This review proposes an explanation for the pathogenesis of those neurodegenerative diseases which result in dementia and the resulting diversity of their disease phenotypes. The explanation is based on five principal observations, specifically: 1) neurodegenerative disease may be the direct consequence of neural ageing; 2) ageing may cause differe...

Purpose: To survey the use of Pearson's correlation coefficient (r) and related statistical methods in the ophthalmic literature, to consider the limitations of r, and to suggest suitable alternative methods of analysis. Recent findings: Searching Ophthalmic and Physiological Optics (OPO), Optometry and Vision Science (OVS), and Clinical and Exp...

Early reviews identified over 20 risk factors associated with Alzheimer's disease (AD) including age, familial inheritance, exposure to aluminium, traumatic brain injury (TBI), and associated co-morbidities such as vascular disease and infection. In the light of recent evidence, this review reconsiders these risk factors, identifies those currently...

There continues to be speculation regarding whether lichens could survive on Mars. Lichens have been described as 'extremophiles' and could potentially withstand some aspects of the hostile environment of the planet especially if they are 'endolithic' and live within the rocks as in some deserts and dry valleys in Antarctica. Lichens, however, are...

Published in: Journel of Astrobiology and Space Science Reviews

Published in: Optometry in Practice

Objectives An observational study to compare the laminar distributions in frontal and temporal cortex of the tau-immunoreactive pathologies in chronic traumatic encephalopathy (CTE) and Alzheimer’s disease neuropathologic change (ADNC). Patients Post-mortem material of (1) four cases of CTE without ADNC, (2) seven cases of CTE with ADNC (CTE/ADNC)...

Alzheimer's disease neuropathologic change (ADNC) in the form of -amyloid (A) deposits is important not only in the pathogenesis of Alzheimer's disease (AD) and Down's syndrome (DS) but also as a 'co-pathology' in disorders such as dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and chronic traumatic encephalopathy (CTE). To com...

Background: Tauopathies are a major group of neurodegenerative disorders characterised by the presence of tau-immunoreactive inclusions in the cytoplasm of neurons and glia. The spread of pathogenic tau along neuroanatomical pathways may play a significant role in the pathogenesis of neurodegenerative disorders. It is hypothesised that such a sprea...

Aims: To characterize the topography of white matter pathology in neuronal intermediate filament inclusion disease (NIFID), a rare subtype of frontotemporal lobar degeneration (FTLD) with "fused in sarcoma" (FUS)-immunoreactive inclusions. Material and methods: Fiber tracts from frontal and temporal lobes of 10 cases of NIFID. Method: Spatial...

Traumatic brain injury (TBI) and its associated concussion are major causes of disability and death. All ages can be affected but children, young adults and the elderly are particularly susceptible. A decline in mortality has resulted in many more individuals living with a disability caused by TBI including those affecting vision. This review descr...

A variety of methods are available for the quantitative description and analysis of neurodegenerative disease. If neurodegenerative disease exists as a series of distinct disorders, then classificatory methods such as hierarchical cluster analysis (HCA) and decision tree analysis (DTA) can be used to classify cases into groups more objectively. If...

Published in: Internal Medicine Review

Lichens exhibit the classic features of stress-tolerant organisms, viz. slow growth rates, considerable longevity, low demand for nutrients, and the presence of specific adaptations to survive in the most inhospitable environments on Earth. The ability of lichens to tolerate the extremes posed by deserts, polar regions, and chemically rich environm...

Purpose: To evaluate, in an amateur sports-playing population, the prevalence of refractive error, the type of vision correction used during sport and attitudes toward different kinds of vision correction used in various types of sports. Method: A questionnaire was used for people engaging in sport and data was collected from sport centres, gyms...

The ‘prion-like’ transfer of pathogenic proteins may play a role in the pathogenesis of frontotemporal lobar degeneration (FTLD). Propagation of such proteins along anatomical pathways may give rise to specific spatial patterns of the ‘signature’ neuronal cytoplasmic inclusions (NCI) characteristic of these disorders. Hence, the spatial patterns of...

Purpose: A common experimental design in ophthalmic research is the repeated-measures design in which at least one variable is a within-subject factor. This design is vulnerable to lack of 'sphericity' which assumes that the variances of the differences among all possible pairs of within-subject means are equal. Traditionally, this design has been...

This chapter describes the visual problems likely to be encountered in Parkinson's disease (PD) and whether such signs are useful in differentiating the parkinsonian syndromes. Visual dysfunction in PD may involve visual acuity, contrast sensitivity, color discrimination, pupil reactivity, saccadic and pursuit eye movements, motion perception, visu...

The objective of this study was to determine whether there is evidence from quantitative morphometry and spatial pattern analysis to support the hypothesis of anatomical spread of α-synuclein in Parkinson's disease dementia (PDD). Hence, clustering of α-synuclein-immunoreactive Lewy bodies (LB), Lewy neurites (LN), and Lewy grains (LG) was studied...

To investigate cortical laminar degeneration in Parkinson’s disease (PD) with dementia (PDD). Changes in density of α-synuclein-immunoreactive Lewy bodies (LB), Lewy neurites (LN), and Lewy grains (LG) together with surviving neurons, abnormally enlarged neurons (EN), vacuoles, and glial cell nuclei were measured across cortical laminae of frontal...

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder which may result from repetitive brain injury. A variety of tau-immunoreactive pathologies are present, including neurofibrillary tangles (NFT), neuropil threads (NT), dot-like grains (DLG), astrocytic tangles (AT), and occasional neuritic plaques (NP). In tauopathies, cellular...

Aims: To characterize white matter pathology in frontotemporal lobar degeneration (FTLD) with TDP-43 proteinopathy (FTLD-TDP) and its relationship to gray matter pathology. Material: Fiber tracts from frontal and temporal lobes of 10 sporadic cases of FTLD and 8 controls. Method: Density and spatial patterns of vacuolation, glial cell nuclei,...

Corticobasal degeneration is a rare, progressive neurodegenerative disease and a member of the ‘parkinsonian’ group of disorders, which also includes Parkinson's disease, progressive supranuclear palsy, dementia with Lewy bodies and multiple system atrophy. The most common initial symptom is limb clumsiness, usually affecting one side of the body,...

Purpose: To investigate neuropathological changes in the superior colliculus in chronic traumatic encephalopathy. Methods: The densities of the tau-immunoreactive neurofibrillary tangles, neuropil threads, dot-like grains, astrocytic tangles, and neuritic plaques, together with abnormally enlarged neurons, typical neurons, vacuolation, and frequ...

Traditional methods of describing and classifying neurodegenerative disease are based on the clinico-pathological concept supported by molecular pathological studies and defined by 'consensus criteria'. Disease heterogeneity, overlap between disorders, and the presence of multiple co-pathologies, however, have questioned the validity and status of...

Factors associated with survival were studied in 84 neuropathologically documented cases of the pre-senile dementia frontotemporal dementia lobar degeneration (FTLD) with transactive response (TAR) DNA-binding protein of 43 kDa (TDP-43) proteinopathy (FTLD-TDP). Kaplan-Meier survival analysis estimated mean survival as 7.9 years (range: 1-19 years,...

Lichenometric dating (lichenometry) involves the use of lichen measurements to estimate the age of exposure of various substrata. Because of low radial growth rates and considerable longevity, species of the crustose lichen genus Rhizocarpon have been the most useful in lichenometry. The primary assumption of lichenometry is that colonization, grow...

Background: The aim was to derive equations for the relationship between unaided vision and age, pupil diameter, iris colour and sphero-cylindrical refractive error. Methods: Data were collected from 663 healthy right eyes of white subjects aged 20 to 70 years. Subjective sphero-cylindrical refractive errors ranged from -6.8 to +9.4 D (mean sphe...

Aims: To quantify tau pathology of chronic traumatic encephalopathy (CTE) and investigate influence of dot-like lesions (DL), brain region, co-morbidity, and sporting career length. Methods: Densities of neurofibrillary tangles (NFT), astrocytic tangles (AT), DL, oligodendroglial inclusions (GI), neuropil threads (NT), vacuoles, neurons, and enl...

Published in: Optometry today

Published in: Journal of Neuropathology and Experimental Neurology 75: 595

Corticobasal degeneration is a rare, progressive neurodegenerative disorder which significantly impairs movement. The most common initial symptom is asymmetric limb clumsiness with or without accompanying rigidity or tremor. Subsequently, the disease progresses to affect gait, and there is a slow progression to influence ipsilateral arms and legs....

Dementia with Lewy bodies ("Lewy body dementia" or "diffuse Lewy body disease") (DLB) is the second most common form of dementia after Alzheimer's disease (AD). Characteristic of DLB are: (1) fluctuating cognitive ability with variations in attention and alertness, (2) recurrent visual hallucinations, and (3) motor features including akinesia, rigi...

This review describes the oculo-visual problems likely to be encountered in Parkinson's disease (PD) with special reference to three questions: (1) are there visual symptoms characteristic of the prodromal phase of PD, (2) is PD dementia associated with specific visual changes, and (3) can visual symptoms help in the differential diagnosis of the p...