81 research outputs found
Persistent homology to analyse 3D faces and assess body weight gain
In this paper, we analyse patterns in face shape variation due to weight gain. We propose the use of persistent homology descriptors to get geometric and topological information about the configuration of anthropometric 3D face landmarks. In this way, evaluating face changes boils down to comparing the descriptors computed on 3D face scans taken at different times. By applying dimensionality reduction techniques to the dissimilarity matrix of descriptors, we get a space in which each face is a point and face shape variations are encoded as trajectories in that space. Our results show that persistent homology is able to identify features which are well related to overweight and may help assessing individual weight trends. The research was carried out in the context of the European project SEMEOTICONS, which developed a multisensory platform which detects and monitors over time facial signs of cardio-metabolic risk
Phenotypic Plasticity and Contemporary Evolution in Introduced Populations: Evidence from Translocated Populations of White Sands Pupfish (Cyrpinodon tularosa)
Contemporary evolution has been shown in a few studies to be an important component of colonization ability, but seldom have researchers considered whether phenotypic plasticity facilitates directional evolution from the invasion event. In the current study, we evaluated body shape divergence of the New Mexico State-threatened White Sands pupfish (Cyprinodon tularosa) that were introduced to brackish, lacustrine habitats at two different time in the recent past (approximately 30 years and 1 year previously) from the same source population (saline river environment). Pupfish body shape is correlated with environmental salinity: fish from saline habitats are characterized by slender body shapes, whereas fish from fresher, yet brackish springs are deep-bodied. In this study, lacustrine populations consisted of an approximately 30-year old population and several 1-year old populations, all introduced from the same source. The body shape divergence of the 30-year old population was significant and greater than any of the divergences of the 1-year old populations (which were for the most part not significant). Nonetheless, all body shape changes exhibited body deepening in less saline environments. We conclude that phenotypic plasticity potentially facilitates directional evolution of body deepening for introduced pupfish populations
Contemporary Evolutionary Divergence for a Protected Species following Assisted Colonization
Contemporary evolution following assisted colonization may increase the probability of persistence for refuge populations established as a bet-hedge for protected species. Such refuge populations are considered "genetic replicates" that might be used for future re-colonization in the event of a catastrophe in the native site. Although maladaptive evolutionary divergence of captive populations is well recognized, evolutionary divergence of wild refuge populations may also occur on contemporary time scales. Thus, refuge populations may lose their "value" as true genetic replicates of the native population. Here, we show contemporary evolutionary divergence in body shape in an approximately 30-year old refuge population of the protected White Sands pupfish (Cyprinodon tularosa) resulting in a body-shape mismatch with its native environment.Geometric morphometic data were collected from C. tularosa cultures raised in experimental mesocosms. Cultures were initiated with fish from the two native populations, plus hybrids, in high or low salinity treatments representing the salinities of the two native habitats. We found that body shape was heritable and that shape variation due to phenotypic plasticity was small compared to shape variation due to population source. C. tularosa from the high salinity population retained slender body shapes and fish from the low salinity population retained deep body shapes, irrespective of mesocosm salinity. These data suggest that the observed divergence of a recently established pupfish population was not explained by plasticity. An analysis of microsatellite variation indicated that no significant genetic drift occurred in the refuge population, further supporting the adaptive nature of changes in body shape. These lines of evidence suggest that body shape divergence of the refuge population reflects a case of contemporary evolution (over a 30-year period).These results suggest assisted colonization can introduce novel, and/or relaxed selection, and lead to unintended evolutionary divergence
The Right to Rehabilitation for People With Dementia: A Codesign Approach to Barriers and Solutions
Introduction: People with dementia of all ages have a human right to equal access to quality health care. Despite evidence regarding its effectiveness, many people living with dementia are unable to access rehabilitation for promoting function and quality of life. Conducted in Australia, this study was designed to (1) explore barriers to access to dementia rehabilitation and (2) identify solutions that improve access to rehabilitation. Methods: People living with dementia (n = 5) and care partners (n = 8) and health professionals (n = 13) were recruited nationally. Experience-based codesign across three virtual workshops was used to understand barriers and design solutions to improve access to rehabilitation treatments. Socio-ecological analyses, using the Levesque Access to Health care framework, were applied to findings regarding barriers and to aid selection of solutions. Results: There was high attendance (92.3%) across the three workshops. Barriers were identified at a user level (including lack of knowledge, transport, cost and difficulty navigating the health, aged care and disability sectors) and health service level (including health professional low dementia knowledge and negative attitudes, inequitable funding models and non-existent or fragmented services). Solutions focused on widespread dementia education and training, including ensuring that people with dementia and their care partners know about rehabilitation therapies and that health professionals, aged care and disability co-ordinators know how to refer to and deliver rehabilitation interventions. Dementia care navigators, changes to Australia's public funding models and specific dementia rehabilitation programmes were also recommended. Conclusions: Barriers to accessing rehabilitation for people with dementia exist at multiple levels and will require a whole-community and systems approach to ensure change. Patient or Public Contribution: People with living experience (preferred term by those involved) were involved at two levels within this research. A Chief Investigator living with dementia was involved in the design of the study and writing of the manuscript. People with living experience, care partners and service providers were participants in the codesign process to identify barriers and design potential solutions
Association of dual decline in cognition and gait speed with risk of dementia in older adults
Importance Dual decline in gait speed and cognition has been found to be associated with increased dementia risk in previous studies. However, it is unclear if risks are conferred by a decline in domain-specific cognition and gait.Objective To examine associations between dual decline in gait speed and cognition (ie, global, memory, processing speed, and verbal fluency) with risk of dementia.Design, Setting, and Participants This cohort study used data from older adults in Australia and the US who participated in a randomized clinical trial testing low-dose aspirin between 2010 and 2017. Eligible participants in the original trial were aged 70 years or older, or 65 years or older for US participants identifying as African American or Hispanic. Data analysis was performed between October 2020 and November 2021Exposures Gait speed, measured at 0, 2, 4, and 6 years and trial close-out in 2017. Cognitive measures included Modified Mini-Mental State examination (3MS) for global cognition, Hopkins Verbal Learning Test-Revised (HVLT-R) for memory, Symbol Digit Modalities (SDMT) for processing speed, and Controlled Oral Word Association Test (COWAT-F) for verbal fluency, assessed at years 0, 1, 3, 5, and close-out. Participants were classified into 4 groups: dual decline in gait and cognition, gait decline only, cognitive decline only, and nondecliners. Cognitive decline was defined as membership of the lowest tertile of annual change. Gait decline was defined as a decline in gait speed of 0.05 m/s or greater per year across the study.Main Outcomes and Measures Dementia (using Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition] criteria) was adjudicated by an expert panel using cognitive tests, functional status, and clinical records. Cox proportional hazard models were used to estimate risk of dementia adjusting for covariates, with death as competing risk.Results Of 19 114 randomized participants, 16 855 (88.2%) had longitudinal gait and cognitive data for inclusion in this study (mean [SD] age, 75.0 [4.4] years; 9435 women [56.0%], 7558 participants [44.8%] with 12 or more years of education). Compared with nondecliners, risk of dementia was highest in the gait plus HVLT-R decliners (hazard ratio [HR], 24.7; 95% CI, 16.3-37.3), followed by the gait plus 3MS (HR, 22.2; 95% CI, 15.0-32.9), gait plus COWAT-F (HR, 4.7; 95% CI, 3.5-6.3), and gait plus SDMT (HR, 4.3; 95% CI, 3.2-5.8) groups. Dual decliners had a higher risk of dementia than those with either gait or cognitive decline alone for 3MS and HVLT-R.Conclusions and Relevance Of domains examined, the combination of decline in gait speed with memory had the strongest association with dementia risk. These findings support the inclusion of gait speed in dementia risk screening assessments
Ectoparasite activity during incubation increases microbial growth on avian eggs
We thank Estefanía López for lab work, and Tomás Pérez-Contreras and Emilio Pagani-Núñez
for facilitating collection of some of the flies used in manipulations. We also thank Ángela
Martínez-García for help with management of ARISA data and Natalia Juárez and Deseada
Parejo for the pictures of owls and roller clutches, respectively. We appreciate the comments
provided by Dr. Adèle Mennerat and five anonymous referees on earlier versions of the
manuscript.All applicable
international, national, and/or institutional guidelines for the care and use of animals were
followed.While direct detrimental effects of parasites on hosts are relatively well documented, other more subtle but potentially important effects of parasitism are yet unexplored. Biological activity of ectoparasites, apart from skin injuries and blood-feeding, often results in blood remains, or parasite faeces that accumulate and modify the host environment. In this way, ectoparasite activities and remains may increase nutrient availability that may favour colonization and growth of microorganisms including potential pathogens. Here, by the experimental addition of hematophagous flies (Carnus hemapterus, a common ectoparasite of birds) to nests of spotless starlings Sturnus unicolor during incubation, we explore this possible side effect of parasitism which has rarely, if ever, been investigated. Results show that faeces and blood remains from parasitic flies on spotless starling eggshells at the end of incubation were more abundant in experimental than in control nests. Moreover, eggshell bacterial loads of different groups of cultivable bacteria including potential pathogens, as well as species richness of bacteria in terms of Operational Taxonomic Units (OTUs), were also higher in experimental nests. Finally, we also found evidence of a link between eggshell bacterial loads and increased embryo mortality, which provides indirect support for a bacterial-mediated negative effect of ectoparasitism on host offspring. Trans-shell bacterial infection might be one of the main causes of embryo death and, consequently, this hitherto unnoticed indirect effect of ectoparasitism might be widespread in nature and could affect our understanding of ecology and evolution of host-parasite interactionsFinancial support was provided by Spanish Ministerio de Economía y
Competitividad and FEDER (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P), by JAE
programme to DMG and MRR, and by Juan de la Cierva and Ramón y Cajal programmes to
GT. All procedures were conducted under licence from the Environmental Department of the
Regional Government of Andalucía, Spain (reference SGYB/FOA/AFR)
Phenotypic plasticity and contemporary evolution in introduced populations: evidence from translocated populations of white sands pupfish (Cyrpinodon tularosa)
Shape - but Not Size - Codivergence between Male and Female Copulatory Structures in Onthophagus Beetles
Genitalia are among the fastest evolving morphological traits in arthropods. Among the many hypotheses aimed at explaining this observation, some explicitly or implicitly predict concomitant male and female changes of genital traits that interact during copulation (i.e., lock and key, sexual conflict, cryptic female choice and pleiotropy). Testing these hypotheses requires insights into whether male and female copulatory structures that physically interact during mating also affect each other's evolution and patterns of diversification. Here we compare and contrast size and shape evolution of male and female structures that are known to interact tightly during copulation using two model systems: (a) the sister species O. taurus (1 native, 3 recently established populations) and O. illyricus, and (b) the species-complex O. fracticornis-similis-opacicollis. Partial Least Squares analyses indicated very little to no correlation between size and shape of copulatory structures, both in males and females. Accordingly, comparing shape and size diversification patterns of genitalia within each sex showed that the two components diversify readily - though largely independently of each other - within and between species. Similarly, comparing patterns of divergence across sexes showed that relative sizes of male and female copulatory organs diversify largely independent of each other. However, performing this analysis for genital shape revealed a signature of parallel divergence. Our results therefore suggest that male and female copulatory structures that are linked mechanically during copulation may diverge in concert with respect to their shapes. Furthermore, our results suggest that genital divergence in general, and co-divergence of male and female genital shape in particular, can evolve over an extraordinarily short time frame. Results are discussed in the framework of the hypotheses that assume or predict concomitant evolutionary changes in male and female copulatory organs
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