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1.
Glob Chang Biol ; 28(11): 3515-3536, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35293658

RESUMO

Offshore platforms, subsea pipelines, wells and related fixed structures supporting the oil and gas (O&G) industry are prevalent in oceans across the globe, with many approaching the end of their operational life and requiring decommissioning. Although structures can possess high ecological diversity and productivity, information on how they interact with broader ecological processes remains unclear. Here, we review the current state of knowledge on the role of O&G infrastructure in maintaining, altering or enhancing ecological connectivity with natural marine habitats. There is a paucity of studies on the subject with only 33 papers specifically targeting connectivity and O&G structures, although other studies provide important related information. Evidence for O&G structures facilitating vertical and horizontal seascape connectivity exists for larvae and mobile adult invertebrates, fish and megafauna; including threatened and commercially important species. The degree to which these structures represent a beneficial or detrimental net impact remains unclear, is complex and ultimately needs more research to determine the extent to which natural connectivity networks are conserved, enhanced or disrupted. We discuss the potential impacts of different decommissioning approaches on seascape connectivity and identify, through expert elicitation, critical knowledge gaps that, if addressed, may further inform decision making for the life cycle of O&G infrastructure, with relevance for other industries (e.g. renewables). The most highly ranked critical knowledge gap was a need to understand how O&G structures modify and influence the movement patterns of mobile species and dispersal stages of sessile marine species. Understanding how different decommissioning options affect species survival and movement was also highly ranked, as was understanding the extent to which O&G structures contribute to extending species distributions by providing rest stops, foraging habitat, and stepping stones. These questions could be addressed with further dedicated studies of animal movement in relation to structures using telemetry, molecular techniques and movement models. Our review and these priority questions provide a roadmap for advancing research needed to support evidence-based decision making for decommissioning O&G infrastructure.


Assuntos
Ecossistema , Peixes , Animais , Invertebrados , Larva , Oceanos e Mares
2.
Exp Aging Res ; 47(2): 131-144, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33357089

RESUMO

Objective: To study whether memory control beliefs predict response to memory training, or change as a result of participating in memory training. Methods: Eighty community based participants with subjective memory complaints Community-based study at UCLA were randomized to one of three conditions: Memory Training, the program consisted of weekly 120-minute classes featuring instruction in three specific strategies: Method of Loci; Chunking Technique; and Face-Name Association, Health Education or Wait-List over seven weeks. All participants underwent pre- and 1-week post-intervention follow-up memory testing for recalling word lists (in serial order and any order) and face-name pairs. Memory control beliefs were assessed at baseline and follow-up using the Memory Controllability Inventory, which consists of four subscales; Present Ability; Potential Improvement; Effort Utility; and Inevitable Decrement. Results: Sixty-three participants (mean age [SD] 68.3 [6.7] years) were included in the analysis. ANCOVA revealed significant group differences in the Present Ability subscale, F2,58 = 4.93, p =.01. Participants in the Memory Training group significantly improved on the Present Ability subscale compared to the Health Education group (mean difference =.96, SE =.31, p =.003, effect size = 0.93). From regression analyses, baseline Memory Controllability Inventory subscales did not significantly predict memory performance after memory training. Conclusions: Baseline memory control beliefs did not predict memory performance following the intervention, but participating in memory training enhanced memory control beliefs about current memory function. These results suggest that participating in memory training can enhance confidence in one's memory ability.


Assuntos
Envelhecimento , Memória , Idoso , Cognição , Humanos , Aprendizagem , Transtornos da Memória/terapia
3.
Mol Ecol ; 27(7): 1586-1602, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29575282

RESUMO

The predominance of self-recruitment in many reef-building corals has fundamental and complex consequences for their genetic diversity, population persistence and responses to climate change. Knowledge of genetic structure over local scales needs to be placed within a broad spatial context, and also integrated with genetic monitoring through time to disentangle these consequences. Here, we examined patterns of genetic diversity over multiple spatio-temporal scales across tropical Australia in the ubiquitous brooding coral, Seriatopora hystrix. We also analysed complimentary environmental and demographic data to elucidate the seascape drivers of these patterns. Large genetic differences were detected between the east vs. west coasts of Australia. In northwest Australia, geographic differentiation dominated genetic structure over multiple scales. However, three sympatric lineages were detected at the largest offshore reef system (Scott Reef). Similar to the differences observed among putative species in eastern Australia, these lineages were associated with different levels of wave exposure. Local genetic structure within the Scott Reef system was relatively stable over 10 years, but temporal differences were observed that reflected small but important genetic changes over a few generations during recovery after severe bleaching. These results highlight the importance of self-recruitment together with occasional longer distance connectivity for the persistence of a metapopulation across spatially and temporally variable environments. Our multidimensional research provides a foundation for further long-term genetic monitoring to inform conservation strategies and highlights that sampling scales, ecological effects and cryptic diversity are important considerations to develop realistic understanding of the evolutionary resilience of corals.


Assuntos
Antozoários/genética , Perfilação da Expressão Gênica , Animais , Austrália , Análise por Conglomerados , Recifes de Corais , Genótipo , Repetições de Microssatélites/genética , Filogeografia , Análise de Componente Principal , Fatores de Tempo
4.
Mol Ecol ; 27(23): 4680-4697, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30308702

RESUMO

The mechanisms that determine patterns of species dispersal are important factors in the production and maintenance of biodiversity. Understanding these mechanisms helps to forecast the responses of species to environmental change. Here, we used a comparative framework and genomewide data obtained through RAD-Seq to compare the patterns of connectivity among breeding colonies for five penguin species with shared ancestry, overlapping distributions and differing ecological niches, allowing an examination of the intrinsic and extrinsic barriers governing dispersal patterns. Our findings show that at-sea range and oceanography underlie patterns of dispersal in these penguins. The pelagic niche of emperor (Aptenodytes forsteri), king (A. patagonicus), Adélie (Pygoscelis adeliae) and chinstrap (P. antarctica) penguins facilitates gene flow over thousands of kilometres. In contrast, the coastal niche of gentoo penguins (P. papua) limits dispersal, resulting in population divergences. Oceanographic fronts also act as dispersal barriers to some extent. We recommend that forecasts of extinction risk incorporate dispersal and that management units are defined by at-sea range and oceanography in species lacking genetic data.


Assuntos
Distribuição Animal , Genética Populacional , Genômica , Spheniscidae/genética , Animais , Regiões Antárticas , Ecossistema , Fluxo Gênico , Variação Genética , Técnicas de Genotipagem , Filogenia , Polimorfismo de Nucleotídeo Único , Spheniscidae/classificação
5.
Am J Geriatr Psychiatry ; 26(3): 266-277, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29246725

RESUMO

OBJECTIVE: Because curcumin's anti-inflammatory properties may protect the brain from neurodegeneration, we studied its effect on memory in non-demented adults and explored its impact on brain amyloid and tau accumulation using 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile positron emission tomography (FDDNP-PET). METHODS: Forty subjects (age 51-84 years) were randomized to a bioavailable form of curcumin (Theracurmin® containing 90 mg of curcumin twice daily [N = 21]) or placebo (N = 19) for 18 months. Primary outcomes were verbal (Buschke Selective Reminding Test [SRT]) and visual (Brief Visual Memory Test-Revised [BVMT-R]) memory, and attention (Trail Making A) was a secondary outcome. FDDNP-PET signals (15 curcumin, 15 placebo) were determined in amygdala, hypothalamus, medial and lateral temporal, posterior cingulate, parietal, frontal, and motor (reference) regions. Mixed effects general linear models controlling for age and education, and effect sizes (ES; Cohen's d) were estimated. RESULTS: SRT Consistent Long-Term Retrieval improved with curcumin (ES = 0.63, p = 0.002) but not with placebo (ES = 0.06, p = 0.8; between-group: ES = 0.68, p = 0.05). Curcumin also improved SRT Total (ES = 0.53, p = 0.002), visual memory (BVMT-R Recall: ES = 0.50, p = 0.01; BVMT-R Delay: ES = 0.51, p = 0.006), and attention (ES = 0.96, p < 0.0001) compared with placebo (ES = 0.28, p = 0.1; between-group: ES = 0.67, p = 0.04). FDDNP binding decreased significantly in the amygdala with curcumin (ES = -0.41, p = 0.04) compared with placebo (ES = 0.08, p = 0.6; between-group: ES = 0.48, p = 0.07). In the hypothalamus, FDDNP binding did not change with curcumin (ES = -0.30, p = 0.2), but increased with placebo (ES = 0.26, p = 0.05; between-group: ES = 0.55, p = 0.02). CONCLUSIONS: Daily oral Theracurmin may lead to improved memory and attention in non-demented adults. The FDDNP-PET findings suggest that symptom benefits are associated with decreases in amyloid and tau accumulation in brain regions modulating mood and memory.


Assuntos
Envelhecimento/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Atenção/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Curcumina/farmacologia , Memória/efeitos dos fármacos , Placa Amiloide/tratamento farmacológico , Proteínas tau/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/administração & dosagem , Encéfalo/diagnóstico por imagem , Curcumina/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Tomografia por Emissão de Pósitrons , Resultado do Tratamento
6.
Mol Ecol ; 26(15): 3883-3897, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28488293

RESUMO

Understanding the boundaries of breeding populations is of great importance for conservation efforts and estimates of extinction risk for threatened species. However, determining these boundaries can be difficult when population structure is subtle. Emperor penguins are highly reliant on sea ice, and some populations may be in jeopardy as climate change alters sea-ice extent and quality. An understanding of emperor penguin population structure is therefore urgently needed. Two previous studies have differed in their conclusions, particularly whether the Ross Sea, a major stronghold for the species, is isolated or not. We assessed emperor penguin population structure using 4,596 genome-wide single nucleotide polymorphisms (SNPs), characterized in 110 individuals (10-16 per colony) from eight colonies around Antarctica. In contrast to a previous conclusion that emperor penguins are panmictic around the entire continent, we find that emperor penguins comprise at least four metapopulations, and that the Ross Sea is clearly a distinct metapopulation. Using larger sample sizes and a thorough assessment of the limitations of different analytical methods, we have shown that population structure within emperor penguins does exist and argue that its recognition is vital for the effective conservation of the species. We discuss the many difficulties that molecular ecologists and managers face in the detection and interpretation of subtle population structure using large SNP data sets, and argue that subtle structure should be taken into account when determining management strategies for threatened species, until accurate estimates of demographic connectivity among populations can be made.


Assuntos
Conservação dos Recursos Naturais , Genética Populacional , Spheniscidae/genética , Animais , Regiões Antárticas , Mudança Climática , Camada de Gelo , Polimorfismo de Nucleotídeo Único , Densidade Demográfica
7.
Alzheimers Dement ; 13(7): 739-748, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28183529

RESUMO

INTRODUCTION: The translocase of outer mitochondrial membrane 40 (TOMM40), which lies in linkage disequilibrium with apolipoprotein E (APOE), has received attention more recently as a promising gene in Alzheimer's disease (AD) risk. TOMM40 influences AD pathology through mitochondrial neurotoxicity, and the medial temporal lobe (MTL) is the most likely brain region for identifying early manifestations of AD-related morphology changes. METHODS: In this study, we examined the effects of TOMM40 using high-resolution magnetic resonance imaging in 65 healthy, older subjects with and without the APOE ε4 AD-risk variant. RESULTS: Examining individual subregions within the MTL, we found a significant relationship between increasing poly-T lengths of the TOMM40 variant and thickness of the entorhinal cortex only in subjects who did not carry the APOE ε4 allele. DISCUSSION: Our data provide support for TOMM40 variant repeat length as an important contributor to AD-like MTL pathology in the absence of APOE ε4.


Assuntos
Apolipoproteína E4/genética , Hipocampo/patologia , Proteínas de Membrana Transportadoras/genética , Idoso , Doença de Alzheimer/genética , Córtex Entorrinal/patologia , Feminino , Genótipo , Voluntários Saudáveis , Humanos , Desequilíbrio de Ligação , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Lobo Temporal/patologia
8.
BMC Evol Biol ; 16: 61, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26975876

RESUMO

BACKGROUND: Models that predict changes in the abundance and distribution of fauna under future climate change scenarios often assume that ecological niche and habitat availability are the major determinants of species' responses to climate change. However, individual species may have very different capacities to adapt to environmental change, as determined by intrinsic factors such as their dispersal ability, genetic diversity, generation time and rate of evolution. These intrinsic factors are usually excluded from forecasts of species' abundance and distribution changes. We aimed to determine the importance of these factors by comparing the impact of the most recent climate regime change, the late Pleistocene glacial-interglacial transition, on two sympatric, ice-dependent meso-predators, the emperor penguin (Aptenodytes forsteri) and Weddell seal (Leptonychotes weddellii). METHODS: We reconstructed the population trend of emperor penguins and Weddell seals in East Antarctica over the past 75,000 years using mitochondrial DNA sequences and an extended Bayesian skyline plot method. We also assessed patterns of contemporary population structure and genetic diversity. RESULTS: Despite their overlapping distributions and shared dependence on sea ice, our genetic data revealed very different responses to climate warming between these species. The emperor penguin population grew rapidly following the glacial-interglacial transition, but the size of the Weddell seal population did not change. The expansion of emperor penguin numbers during the warm Holocene may have been facilitated by their higher dispersal ability and gene flow among colonies, and fine-scale differences in preferred foraging locations. CONCLUSIONS: The vastly different climate change responses of two sympatric ice-dependent predators suggests that differing adaptive capacities and/or fine-scale niche differences can play a major role in species' climate change responses, and that adaptive capacity should be considered alongside niche and distribution in future species forecasts.


Assuntos
Caniformia/genética , Mudança Climática , DNA Mitocondrial/genética , Evolução Molecular , Spheniscidae/genética , Animais , Regiões Antárticas , Teorema de Bayes , Evolução Biológica , Caniformia/fisiologia , Ecossistema , Genética Populacional , Camada de Gelo , Spheniscidae/fisiologia , Simpatria
9.
BMC Evol Biol ; 16(1): 211, 2016 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-27733109

RESUMO

BACKGROUND: Seabirds are important components of marine ecosystems, both as predators and as indicators of ecological change, being conspicuous and sensitive to changes in prey abundance. To determine whether fluctuations in population sizes are localised or indicative of large-scale ecosystem change, we must first understand population structure and dispersal. King penguins are long-lived seabirds that occupy a niche across the sub-Antarctic zone close to the Polar Front. Colonies have very different histories of exploitation, population recovery, and expansion. RESULTS: We investigated the genetic population structure and patterns of colonisation of king penguins across their current range using a dataset of 5154 unlinked, high-coverage single nucleotide polymorphisms generated via restriction site associated DNA sequencing (RADSeq). Despite breeding at a small number of discrete, geographically separate sites, we find only very slight genetic differentiation among colonies separated by thousands of kilometers of open-ocean, suggesting migration among islands and archipelagos may be common. Our results show that the South Georgia population is slightly differentiated from all other colonies and suggest that the recently founded Falkland Island colony is likely to have been established by migrants from the distant Crozet Islands rather than nearby colonies on South Georgia, possibly as a result of density-dependent processes. CONCLUSIONS: The observed subtle differentiation among king penguin colonies must be considered in future conservation planning and monitoring of the species, and demographic models that attempt to forecast extinction risk in response to large-scale climate change must take into account migration. It is possible that migration could buffer king penguins against some of the impacts of climate change where colonies appear panmictic, although it is unlikely to protect them completely given the widespread physical changes projected for their Southern Ocean foraging grounds. Overall, large-scale population genetic studies of marine predators across the Southern Ocean are revealing more interconnection and migration than previously supposed.


Assuntos
Migração Animal/fisiologia , Ecossistema , Genética Populacional , Spheniscidae/genética , Animais , Regiões Antárticas , Teorema de Bayes , Análise por Conglomerados , Análise Discriminante , Variação Genética , Técnicas de Genotipagem , Geografia , Filogeografia , Densidade Demográfica , Análise de Componente Principal
10.
Glob Chang Biol ; 22(2): 474-93, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26391440

RESUMO

The Southern Ocean ecosystem is undergoing rapid physical and biological changes that are likely to have profound implications for higher-order predators. Here, we compare the long-term, historical responses of Southern Ocean predators to climate change. We examine palaeoecological evidence for changes in the abundance and distribution of seabirds and marine mammals, and place these into context with palaeoclimate records in order to identify key environmental drivers associated with population changes. Our synthesis revealed two key factors underlying Southern Ocean predator population changes; (i) the availability of ice-free ground for breeding and (ii) access to productive foraging grounds. The processes of glaciation and sea ice fluctuation were key; the distributions and abundances of elephant seals, snow petrels, gentoo, chinstrap and Adélie penguins all responded strongly to the emergence of new breeding habitat coincident with deglaciation and reductions in sea ice. Access to productive foraging grounds was another limiting factor, with snow petrels, king and emperor penguins all affected by reduced prey availability in the past. Several species were isolated in glacial refugia and there is evidence that refuge populations were supported by polynyas. While the underlying drivers of population change were similar across most Southern Ocean predators, the individual responses of species to environmental change varied because of species specific factors such as dispersal ability and environmental sensitivity. Such interspecific differences are likely to affect the future climate change responses of Southern Ocean marine predators and should be considered in conservation plans. Comparative palaeoecological studies are a valuable source of long-term data on species' responses to environmental change that can provide important insights into future climate change responses. This synthesis highlights the importance of protecting productive foraging grounds proximate to breeding locations, as well as the potential role of polynyas as future Southern Ocean refugia.


Assuntos
Mudança Climática/história , Animais , História Antiga , Camada de Gelo , Oceanos e Mares , Dinâmica Populacional , Reprodução
11.
Am J Geriatr Psychiatry ; 24(9): 729-37, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27421618

RESUMO

OBJECTIVE: Exercise and diet impact body composition, but their age-related brain effects are unclear at the molecular imaging level. To address these issues, the authors determined whether body mass index (BMI), physical activity, and diet relate to brain positron emission tomography (PET) of amyloid plaques and tau tangles using 2-(1-(6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile (FDDNP). METHODS: Volunteers (N = 44; mean age: 62.6 ± 10.7 years) with subjective memory impairment (N = 24) or mild cognitive impairment (MCI; N = 20) were recruited by soliciting for memory complaints. Levels of physical activity and extent of following a Mediterranean-type diet were self-reported. FDDNP-PET scans assessed plaque/tangle binding in Alzheimer disease-associated regions (frontal, parietal, medial and lateral temporal, posterior cingulate). Mixed models controlling for known covariates examined BMI, physical activity, and diet in relation to FDDNP-PET. RESULTS: MCI subjects with above normal BMI (>25) had higher FDDNP-PET binding compared with those with normal BMI (1.11(0.03) versus 1.08(0.03), ES = 1.04, t(35) = 3.3, p = 0.002). Greater physical activity was associated with lower FDDNP-PET binding in MCI subjects (1.07(0.03) versus 1.11(0.03), ES = 1.13, t(35) = -3.1, p = 0.004) but not in subjects with subjective memory impairment (1.07(0.03) versus 1.07(0.03), ES = 0.02, t(35) = -0.1, p = 0.9). Healthier diet related to lower FDDNP-PET binding, regardless of cognitive status (1.07(0.03) versus 1.09(0.02), ES = 0.72, t(35) = -2.1, p = 0.04). CONCLUSION: These preliminary findings are consistent with a relationship between risk modifiersand brain plaque/tangle deposition in nondemented individuals and supports maintenance of normal body weight, regular physical activity, and healthy diet to protect the brain during aging. (clinicaltrials.gov; NCT00355498).


Assuntos
Envelhecimento , Encéfalo , Disfunção Cognitiva , Dieta Mediterrânea/psicologia , Exercício Físico , Transtornos da Memória , Autoavaliação (Psicologia) , Idoso , Envelhecimento/fisiologia , Envelhecimento/psicologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Feminino , Humanos , Masculino , Transtornos da Memória/diagnóstico , Transtornos da Memória/psicologia , Pessoa de Meia-Idade , Emaranhados Neurofibrilares/patologia , Placa Amiloide/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Fatores de Proteção
12.
Glob Chang Biol ; 21(6): 2215-26, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25728986

RESUMO

The relationship between population structure and demographic history is critical to understanding microevolution and for predicting the resilience of species to environmental change. Using mitochondrial DNA from extant colonies and radiocarbon-dated subfossils, we present the first microevolutionary analysis of emperor penguins (Aptenodytes forsteri) and show their population trends throughout the last glacial maximum (LGM, 19.5-16 kya) and during the subsequent period of warming and sea ice retreat. We found evidence for three mitochondrial clades within emperor penguins, suggesting that they were isolated within three glacial refugia during the LGM. One of these clades has remained largely isolated within the Ross Sea, while the two other clades have intermixed around the coast of Antarctica from Adélie Land to the Weddell Sea. The differentiation of the Ross Sea population has been preserved despite rapid population growth and opportunities for migration. Low effective population sizes during the LGM, followed by a rapid expansion around the beginning of the Holocene, suggest that an optimum set of sea ice conditions exist for emperor penguins, corresponding to available foraging area.


Assuntos
Camada de Gelo , Refúgio de Vida Selvagem , Spheniscidae/genética , Animais , Regiões Antárticas , Evolução Biológica , Mudança Climática , DNA Mitocondrial , Fósseis , Filogeografia , Densidade Demográfica , Spheniscidae/fisiologia
13.
Am J Geriatr Psychiatry ; 22(4): 362-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23567426

RESUMO

OBJECTIVES: To determine whether psychological well-being in people with mild cognitive impairment (MCI), a risk state for Alzheimer disease (AD), is associated with in vivo measures of brain pathology. METHODS: Cross-sectional clinical assessments and positron emission tomography (PET) scans after intravenous injections of 2-(1-{6-[(2-[F18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP), a molecule that binds to plaques and tangles, were performed on middle-aged and older adults at a university research institute. Volunteers were aged 40-85 years with MCI (N = 35) or normal cognition (N = 29) without depression or anxiety. Statistical analyses included general linear models, using regional FDDNP-PET binding values as dependent variables and the Vigor-Activity subscale of the Profile of Mood States (POMS) as the independent variable, covarying for age. The POMS is a self-rated inventory of 65 adjectives that describe positive and negative feelings. RESULTS: Scores on the POMS Vigor-Activity subscale were inversely associated with degree of FDDNP binding in the posterior cingulate cortex (r = -0.35, p = 0.04) in the MCI group but not in the control group. CONCLUSION: Psychological well-being, as indicated by self-reports of greater vigor and activity, is associated with lower FDDNP-PET binding in the posterior cingulate cortex, a region involved in emotional regulation, in individuals with MCI but not in those with normal cognition. These findings are consistent with previous work indicating that deposition of brain amyloid plaques and tau tangles may result in noncognitive and cognitive symptoms in persons at risk for AD.


Assuntos
Peptídeos beta-Amiloides , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Emaranhados Neurofibrilares/diagnóstico por imagem , Satisfação Pessoal , Placa Amiloide/diagnóstico por imagem , Proteínas tau , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos
14.
Proc Natl Acad Sci U S A ; 108(51): 20760-5, 2011 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-22106308

RESUMO

Old age and possession of the APOE-4 allele are the two main risk factors for developing later onset Alzheimer's Disease (AD). Carriers of the APOE-4 allele have known differences in intrinsic functional brain network activity across the life span. These individuals also demonstrate specific regional differences in gray and white matter gross structure. However, the relationship of these variations to whole brain structural network connectivity remains unclear. We performed diffusion tensor imaging (DTI), T1 structural imaging, and cognitive testing on aging APOE-4 noncarriers (n = 30; mean age = 63.8±8.3) and APOE-4 carriers (n = 25; mean age = 60.8 ±9.7). Fiber tractography was used to derive whole brain structural graphs, and graph theory was applied to assess structural network properties. Network communication efficiency was determined for each network by quantifying local interconnectivity, global integration, and the balance between these, the small worldness. Relative to noncarriers, APOE-4 carriers demonstrated an accelerated age-related loss of mean local interconnectivity (r = -0.64, P ≤ 0.01) and regional local interconnectivity decreases in the precuneus (r = -0.64), medial orbitofrontal cortex (r = -0.5), and lateral parietal cortex (r = -0.54). APOE-4 carriers also showed significant age-related loss in mean cortical thickness (r = -0.52, P < 0.05). Cognitively, APOE-4 carriers had significant negative correlations of age and performance on two episodic memory tasks (P < 0.05). This genotype-specific pattern of structural connectivity change with age thus appears related to changes in gross cortical structure and cognition, potentially affecting the rate and/or spatial distribution of AD-related pathology.


Assuntos
Envelhecimento , Apolipoproteína E4/genética , Encéfalo/fisiologia , Adulto , Idoso , Alelos , Encéfalo/metabolismo , Mapeamento Encefálico/métodos , Cognição , Imagem de Tensor de Difusão/métodos , Feminino , Genótipo , Heterozigoto , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Fatores de Risco
15.
Drugs R D ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958918

RESUMO

BACKGROUND: Pegfilgrastim-cbqv/CHS-1701 (UDENYCA®) (hereafter referred to as pegfilgrastim-cbqv) was approved in 2018 by the US Food and Drug Administration as a biosimilar for pegfilgrastim (Neulasta®) (hereafter referred to as pegfilgrastim). Both pegfilgrastim-cbqv and pegfilgrastim are conjugates of recombinant human granulocyte colony stimulating factor (r-metHuG-CSF) with a 20 kDa polyethylene glycol (PEG) indicated to decrease the incidence of infection, as manifested by febrile neutropenia, in patients receiving myelosuppressive anticancer drugs. The demonstration of analytical similarity for PEG-protein conjugates presents unique challenges since both the protein and PEG attributes must be characterized. OBJECTIVE: The current study demonstrates the analytical similarity of pegfilgrastim-cbqv and the reference product, pegfilgrastim. In addition to the physicochemical and functional characterization of the protein, the study assessed attributes specific to PEGylation including PEG size and polydispersity, site of attachment, linker composition, and PEGylation process-related variants. METHODS: The structural, functional, and stability attributes of pegfilgrastim-cbqv and pegfilgrastim were compared using state-of-the-art analytical methods. For the protein, the primary structure, disulfide structure, and secondary and tertiary structures were assessed using traditional protein characterization techniques such as mass spectrometry (MS), circular dichroism (CD), intrinsic fluorescence, and differential scanning calorimetry (DSC), as well as more advanced techniques such as two-dimensional (2D) nuclear magnetic resonance (NMR) and hydrogen deuterium exchange (HDX). For the PEG moiety, the site of attachment, occupancy, linker composition, size and polydispersity were compared using mass spectrometry (both intact and after endoprotease digestion), multiangle light scattering detection (MALS), and Edman degradation. Purity assessments included the assessment of both protein variants and PEGylation variants using chromatographic and electrophoretic analytical separation techniques. The functional similarity between pegfilgrastim-cbqv and pegfilgrastim was compared using both a cell-based bioassay and surface plasmon resonance (SPR). The degradation rates and stability profiles were compared under accelerated and stressed conditions. RESULTS: Biosimilarity was demonstrated by a thorough assessment of physiochemical and functional attributes, as well as comparative stability, of pegfilgrastim-cbqv relative to pegfilgrastim. These studies demonstrated identical primary structure and disulfide structure, highly similar secondary and tertiary structure, as well as functional similarity. The impurity profile of pegfilgrastim-cbqv was comparable to that of pegfilgrastim with only minor differences in PEGylation variants and a slight offset in the PEG molar mass. These differences were not clinically relevant. The degradation profiles were qualitatively and quantitatively similar under accelerated and stress conditions. CONCLUSION: The structural, functional, and stability data demonstrate that pegfilgrastim-cbqv is highly similar to the reference product, pegfilgrastim.

16.
Geriatrics (Basel) ; 9(2)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38525754

RESUMO

INTRODUCTION: Adopting healthy lifestyle behaviors has the potential to slow cognitive decline in older adults by reducing risks associated with dementia. Curriculum-based group health coaching may aid in establishing behavior change centered for dementia risk factors. METHODS: In this pilot clinical care patient group study (n = 6), we examined the effects of a six-month online Cognitive Health Program combined with a weekly telehealth support group led by the course creator, and personalized health optimization by a collaborating physician, in older adults with subjective cognitive decline. Cognition was assessed at baseline and post-intervention using a computerized battery. RESULTS: Cognitive changes were estimated with nonparametric tests and effect sizes (Cohen's d). Results showed significant improvements in global cognition (p < 0.03, d = 1.6), spatial planning (p < 0.01, d = 2.3), and visuospatial processing (p < 0.05, d = 1.1) compared to baseline. Participants reported high levels of satisfaction with the virtual group format and online curriculum. CONCLUSIONS: This small pilot study suggests that a virtual six-month personalized health coaching group with self-paced online health education is feasible and potentially efficacious for improving cognition in participants with subjective cognitive complaints. This format may facilitate behavior change to slow cognitive decline. Future studies should include a control group, a larger, more diverse sample as well as assessing mood and other subjective measures.

17.
Am J Geriatr Psychiatry ; 21(7): 655-63, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23602310

RESUMO

OBJECTIVES: Research indicates an association between stimulating mental activities and better memory performance as people age, but studies on computerized mental stimulation programs are limited. We explored whether computerized brain training exercises improved cognitive performance in older adults. METHODS: In local retirement communities, a convenience sample was randomized into an intervention group (N = 36), who used a computer program 5 days a week for 20-25 minutes each day, or a wait-list control group (N = 33). All were older adults without dementia (mean age: 81.8 years; SD: 6.1; 67% female). Neuropsychological testing was completed at baseline (Time 1), 2 months (Time 2), and 6 months (Time 3). Three cognitive domains (Immediate Memory, Delayed Memory, Language) were compared in the two groups as a function of time using mixed models. RESULTS: The intervention group used the computerized program (Brain Fitness, Dakim Inc., Santa Monica, CA) for an average of 43 (SD: 4.4) sessions by Time 2 and 81 (SD: 37.5) sessions by Time 3. Mixed models examining cognitive domains as function of time revealed significant group differences in Delayed Memory (F(2,72) = 4.7, p = 0.01) but not Immediate Memory and Language; no significant improvements were noted for the control group. Among all participants, anyone playing at least 40 sessions over the 6 months improved in all three domains (Immediate Memory, Delayed Memory, and Language). CONCLUSION: Participating in a computerized brain exercise program over 6 months improves cognitive abilities in older adults. These results extend literature indicating the benefit of training exercises, whether in a classroom format or via a computerized self-paced program.


Assuntos
Envelhecimento/psicologia , Cognição , Reserva Cognitiva , Memória , Terapia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Testes Neuropsicológicos
18.
Drugs R D ; 23(4): 377-395, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37632627

RESUMO

BACKGROUND: Adalimumab-aqvh/CHS-1420 (YUSIMRYTM) (hereafter referred to as adalimumab-aqvh) was recently approved by the US Food and Drug Administration as a biosimilar for adalimumab. OBJECTIVE: The current study was conducted to investigate the analytical similarity of adalimumab-aqvh and the reference product, adalimumab. METHODS: The structural, functional, and stability attributes of adalimumab-aqvh and adalimumab were compared using state-of-the-art assays. The primary structure, disulfide structure, glycan profile, secondary and tertiary structures, molar mass, size variants, free thiol, charge variants, hydrophobic variants, post-translational modifications, subvisible particles, host cell proteins, and protein concentration were investigated. The functional similarity between adalimumab-aqvh and adalimumab was demonstrated by comparing fragment antigen-binding (Fab)-associated and fragment crystallizable (Fc)-associated biological activities. The stability of adalimumab-aqvh and of adalimumab was compared through forced degradation. RESULTS: The structural attributes of adalimumab-aqvh were identical to those of adalimumab or met the similarity criteria, with a few exceptions. Adalimumab-aqvh and adalimumab exhibited comparable stability profiles and functional activities. Any observed differences in the physiochemical attributes did not impact the conclusion of similarity because they did not influence any functional activities related to the adalimumab mechanism of action. CONCLUSION: The structural, functional, and stability data provide convincing evidence of biosimilarity between adalimumab-aqvh and the reference product, adalimumab.


Assuntos
Medicamentos Biossimilares , Humanos , Adalimumab/química , Adalimumab/farmacologia , Medicamentos Biossimilares/química
19.
PLoS One ; 18(8): e0289805, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37585439

RESUMO

Key ecological features (KEFs) are elements of Australia's Commonwealth marine environment considered to be important for biodiversity or ecosystem function, yet many KEFs are poorly researched, which can impede effective decision-making about future development and conservation. This study investigates a KEF positioned over the Last Glacial Maximum (LGM) shoreline on the northwest shelf of Australia (known as the 'Ancient Coastline at ~125m depth contour'; AC125). Seafloor bathymetry, sedimentology and benthic habitats were characterised within five study areas using multibeam sonar, sediment samples and towed video imagery. Direct evidence for the existence of a palaeoshoreline formed during the LGM was not found, however candidate areas to find palaeoshoreline material at or just below the modern seabed were discovered. Approximately 98% of the seabed surveyed was comprised of unconsolidated soft sediment habitat (mud/sand/silt) supporting negligible epibenthic biota. The prevalence of soft sediment suggests that post-glacial sediments have infilled parts of the palaeoshoreline, with cross-shelf, probably tidal currents in the northern section of the study area responsible for some of the sediment mobilisation and southern study areas more influenced by oceanic conditions. Within study areas, total biotic cover ranged from 0.02% to 1.07%. Of the biota encountered, most comprised filter feeder organisms (including gorgonians, sponges, and whip corals) whose distribution was associated with pockets of consolidated hard substrate. Benthic community composition varied with both study area and position in relation to the predicted AC125. In general, consolidated substrate was proportionally higher in water shallower than the AC125 compared to on the AC125 or deeper than the AC125. Spatially continuous maps of predicted benthic habitat classes (pre-determined benthic communities) in each study area were developed to characterise biodiversity. Spatial modelling corroborated depth and large-scale structural complexity of the seafloor as surrogates for predicting likely habitat class. This study provides an important assessment of the AC125 and shows that if a distinct coastline exists in the areas we surveyed, it is now largely buried and as such does not provide a unique hard substrate habitat. However, much work remains to fully locate and map the ancient coastline within the vast region of the AC125 and additional surveys in shallow waters adjacent to the AC125 may identify whether some sections lie outside the currently defined KEF.


Assuntos
Antozoários , Ecossistema , Animais , Austrália Ocidental , Biodiversidade , Biota
20.
J Alzheimers Dis ; 91(3): 999-1006, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36530088

RESUMO

BACKGROUND: Strength and mobility are essential for activities of daily living. With aging, weaker handgrip strength, mobility, and asymmetry predict poorer cognition. We therefore sought to quantify the relationship between handgrip metrics and volumes quantified on brain magnetic resonance imaging (MRI). OBJECTIVE: To model the relationships between handgrip strength, mobility, and MRI volumetry. METHODS: We selected 38 participants with Alzheimer's disease dementia: biomarker evidence of amyloidosis and impaired cognition. Handgrip strength on dominant and non-dominant hands was measured with a hand dynamometer. Handgrip asymmetry was calculated. Two-minute walk test (2MWT) mobility evaluation was combined with handgrip strength to identify non-frail versus frail persons. Brain MRI volumes were quantified with Neuroreader. Multiple regression adjusting for age, sex, education, handedness, body mass index, and head size modeled handgrip strength, asymmetry and 2MWT with brain volumes. We modeled non-frail versus frail status relationships with brain structures by analysis of covariance. RESULTS: Higher non-dominant handgrip strength was associated with larger volumes in the hippocampus (p = 0.02). Dominant handgrip strength was related to higher frontal lobe volumes (p = 0.02). Higher 2MWT scores were associated with larger hippocampal (p = 0.04), frontal (p = 0.01), temporal (p = 0.03), parietal (p = 0.009), and occipital lobe (p = 0.005) volumes. Frailty was associated with reduced frontal, temporal, and parietal lobe volumes. CONCLUSION: Greater handgrip strength and mobility were related to larger hippocampal and lobar brain volumes. Interventions focused on improving handgrip strength and mobility may seek to include quantified brain volumes on MR imaging as endpoints.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Idoso , Atividades Cotidianas , Força da Mão , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Hipocampo
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