Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
PeerJ ; 12: e17591, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38948213

RESUMO

Eight fossil tetrapod footprints from lake-shore deposits in the Lower Jurassic Moenave Formation at the St. George Dinosaur Discovery Site (SGDS) in southwestern Utah cannot be assigned to the prevalent dinosaurian (Anomoepus, Eubrontes, Gigandipus, Grallator, Kayentapus) or crocodyliform (Batrachopus) ichnotaxa at the site. The tridactyl and tetradactyl footprints are incomplete, consisting of digit- and digit-tip-only imprints. Seven of the eight are likely pes prints; the remaining specimen is a possible manus print. The pes prints have digit imprint morphologies and similar anterior projections and divarication angles to those of Brasilichnium, an ichnotaxon found primarily in eolian paleoenvironments attributed to eucynodont synapsids. Although their incompleteness prevents clear referral to Brasilichnium, the SGDS tracks nevertheless suggest a eucynodont track maker and thus represent a rare, Early Mesozoic occurrence of such tracks outside of an eolian paleoenvironment.


Assuntos
Fósseis , Utah , Animais , Dinossauros/anatomia & histologia , Paleontologia
2.
JHEP Rep ; 6(1): 100937, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38169900

RESUMO

Background & Aims: Micro-elimination of hepatitis C virus (HCV) in high-risk populations is a feasible approach towards achieving the World Health Organization's targets for viral hepatitis elimination by 2030. Prisons represent an area of high HCV prevalence and so initiatives that improve testing and treatment of residents are needed to eliminate HCV from prisons. This initiative aimed to improve the HCV screening and treatment rates of new residents arriving at prisons in England. Methods: A rapid test and treat pathway was developed and implemented in 47 prisons in England between May 2019 and October 2021 as a healthcare service improvement initiative. Prison healthcare staff performed opt-out HCV testing for all new residents at each prison within 7 days of arrival, and those who were positive for HCV RNA were offered treatment with direct-acting antivirals (DAAs). The Hepatitis C Trust provided peer support for all residents on treatment and those who were released into the community. Results: Of 107,260 new arrivals, 98,882 (92.2%) were offered HCV antibody testing, 63,137 (63.9%) were tested and 1,848 were treated. Testing rates increased from 53.7% in Year 1 to 86.0% in Year 3. Between May 2020 and October 2021, 40,727 residents were tested, 2,286 residents were positive for HCV antibodies and 940 residents were HCV RNA positive, giving an antibody prevalence of 5.6% and an RNA prevalence of 2.3%. A total of 921 residents were referred for treatment and 915 initiated DAA treatment (97.3% of whom were HCV RNA positive). Conclusions: This initiative showed that an opt-out HCV test and treat initiative in prison receptions is feasible and can be adapted to the needs of individual prisons as a viable way to achieve HCV micro-elimination. Impact and implications: Prisons represent an area of high HCV prevalence and so initiatives that improve testing and treatment of residents are needed to eliminate HCV from prisons. The reception testing protocol improved HCV screening in new arrivals across 47 prisons in England and could be a viable way for countries to achieve HCV micro-elimination in their prison systems. The reception testing protocol presented here can be adapted to the individual needs of prisons, globally, to improve HCV screening and treatment in this setting.

3.
Alzheimers Dement ; 9(2): 160-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23266004

RESUMO

Alzheimer's disease (AD) is an epidemic facing the entire world. Increased knowledge gained during the past 25 years indicates that AD falls along a clinical and neuropathological spectrum represented as a continuum that extends from preclinical disease in which there are no symptoms, through early symptomatic phases, and finally to AD dementia. The Alzheimer's research community recognizes that imaging, body fluids, and cognitive biomarkers contribute to enhanced diagnostic confidence for AD. There has also been emerging consensus regarding the use of AD biomarkers in clinical trials. The use of biomarkers in clinical trials and practice is hampered by the lack of standardization. In response to the emerging need for standardization, an international meeting of AD researchers was held in Melbourne, Australia, in March 2012 to bring together key researchers, clinicians, industry, and regulatory stakeholders with the aim of generating consensus on standardization and validation of cognitive, imaging, and fluid biomarkers, as well as lifestyle parameters used in research centers worldwide.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/terapia , Biomarcadores/análise , Ensaios Clínicos como Assunto/normas , Consenso , Humanos
4.
Biol Rev Camb Philos Soc ; 97(3): 960-1004, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34991180

RESUMO

Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.


Assuntos
Escamas de Animais , Carcinoma de Células Escamosas , Dinossauros , Animais , Evolução Biológica , Aves , Dinossauros/anatomia & histologia , Plumas/anatomia & histologia , Fósseis , Osteogênese , Filogenia
5.
PeerJ ; 9: e10640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33569249

RESUMO

New invertebrate trace fossils from the Lower Jurassic Moenave Formation at the St. George Dinosaur Discovery Site at Johnson Farm (SGDS) continue to expand the ichnofauna at the site. A previously unstudied arthropod locomotory trace, SGDS 1290, comprises two widely spaced, thick, gently undulating paramedial impressions flanked externally by small, tapered to elongate tracks with a staggered to alternating arrangement. The specimen is not a variant of any existing ichnospecies, but bears a striking resemblance to modern, experimentally generated crayfish walking traces, suggesting a crayfish or crayfish-like maker for the fossil. Because of its uniqueness, we place it in a new ichnospecies, Siskemia eurypyge. It is the first fossil crayfish or crayfish-like locomotion trace ever recorded.

6.
Nat Ecol Evol ; 3(2): 200-206, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30664698

RESUMO

The Carboniferous-Permian transition (CPT) was Earth's last pre-Quaternary icehouse-greenhouse transition, recording major shifts in late Palaeozoic climate regimes and increased continental seasonality over approximately 40 Myr. Its parallels to Quaternary climate change have inspired recent investigations into the impacts of purported rainforest collapse on palaeotropical vertebrate diversity, but little is known about how the protracted spatial dynamics of this transition impacted the emergence of modern tetrapod lineages. Here, we apply ecological ordinance analyses on a dataset of 286 CPT fossil vertebrate localities binned across four physiographic regions forming a palaeoequatorial transect. Our results clarify the spatiotemporal expansion of land-living vertebrates, demonstrating that the reduction of tropical wetlands accommodated emerging dryland-adapted amniote faunas from a western Pangaean epicentre. We call this west-east lag the 'Vaughn-Olson model': CPT climatic transitions were regionally diachronous with delayed proliferation of amniote-dominated dryland assemblages in the east. By combining our ecological analyses with a phylogenetic approach, we demonstrate that this pattern also applies to some co-occurring total-group amphibians, suggesting that there was pervasive selection for such dryland adaptations across the crown tetrapod tree, in contrast with stem tetrapods and 'fishes'.


Assuntos
Distribuição Animal , Biodiversidade , Evolução Biológica , Mudança Climática , Vertebrados , Animais , Fósseis , Paleontologia , Floresta Úmida
7.
R Soc Open Sci ; 6(5): 182087, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31218034

RESUMO

The enigmatic tetrapod Acherontiscus caledoniae from the Pendleian stage of the Early Carboniferous shows heterodontous and durophagous teeth, representing the earliest known examples of significant adaptations in tetrapod dental morphology. Tetrapods of the Late Devonian and Early Carboniferous (Mississippian), now known in some depth, are generally conservative in their dentition and body morphologies. Their teeth are simple and uniform, being cone-like and sometimes recurved at the tip. Modifications such as keels occur for the first time in Early Carboniferous Tournaisian tetrapods. Acherontiscus, dated as from the Pendleian stage, is notable for being very small with a skull length of about 15 mm, having an elongate vertebral column and being limbless. Cladistic analysis places it close to the Early Carboniferous adelospondyls, aïstopods and colosteids and supports the hypothesis of 'lepospondyl' polyphyly. Heterodonty is associated with a varied diet in tetrapods, while durophagy suggests a diet that includes hard tissue such as chitin or shells. The mid-Carboniferous saw a significant increase in morphological innovation among tetrapods, with an expanded diversity of body forms, skull shapes and dentitions appearing for the first time.

8.
J Neuroimmunol ; 180(1-2): 40-9, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16996143

RESUMO

Though independent findings suggest roles for the allergic arm of the immune system and myelin-reactive antibodies in MS, myelin-reactive IgE has not been investigated. We have developed a radioimmunoassay that measures reactive IgE, IgG and IgA against short (5-6-mers) myelin protein-derived peptides bearing little to no sequence identity with other human proteins, and which might therefore be targets of a CNS-specific autoimmune attack. Here we show that, irrespective of clinical subtype, MS patients' sera are characterized by a higher frequency of measurable IgE against the peptides. Moreover, in controls with measurable IgE reactive against test peptides, IgG or IgA reactive with the same peptide epitopes is almost always present in vastly greater quantities, whereas in MS subjects peptide-reactive IgA or IgG is often undetectable. The sensitivity of the full assay, when considering overall positive a serum sample that has detectable autoreactive IgE without other competing Igs, is 69% (S.E.: 5%), with a specificity of 87% (S.E.: 9%). We speculate that IgE reactive against CNS target antigens may have both diagnostic and pathogenic significance, particularly if other peptide-specific, potentially blocking Igs are absent.


Assuntos
Autoanticorpos/imunologia , Imunoglobulina E/imunologia , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Proteínas da Mielina/imunologia , Fragmentos de Peptídeos/imunologia , Adulto , Autoimunidade/imunologia , Estudos Transversais , Epitopos/imunologia , Feminino , Humanos , Imunoglobulina E/análise , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Valor Preditivo dos Testes , Radioimunoensaio/métodos , Regulação para Cima/imunologia
9.
PLoS One ; 5(11): e14075, 2010 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-21124919

RESUMO

BACKGROUND: Basal iguanodontian dinosaurs were extremely successful animals, found in great abundance and diversity almost worldwide during the Early Cretaceous. In contrast to Europe and Asia, the North American record of Early Cretaceous basal iguanodonts has until recently been limited largely to skulls and skeletons of Tenontosaurus tilletti. METHODOLOGY/PRINCIPAL FINDINGS: Herein we describe two new basal iguanodonts from the Yellow Cat Member of the Cedar Mountain Formation of eastern Utah, each known from a partial skull and skeleton. Iguanacolossus fortis gen. et sp. nov. and Hippodraco scutodens gen. et sp. nov. are each diagnosed by a single autapomorphy and a unique combination of characters. CONCLUSIONS/SIGNIFICANCE: Iguanacolossus and Hippodraco add greatly to our knowledge of North American basal iguanodonts and prompt a new comprehensive phylogenetic analysis of basal iguanodont relationships. This analysis indicates that North American Early Cretaceous basal iguanodonts are more basal than their contemporaries in Europe and Asia.


Assuntos
Evolução Biológica , Osso e Ossos/anatomia & histologia , Dinossauros/anatomia & histologia , Fósseis , Animais , Ásia , Biodiversidade , Dinossauros/classificação , Dinossauros/crescimento & desenvolvimento , Europa (Continente) , Esqueleto , Crânio/anatomia & histologia , Especificidade da Espécie , Fatores de Tempo , Utah
10.
PLoS One ; 4(3): e4591, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19259260

RESUMO

BACKGROUND: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. CONCLUSIONS/SIGNIFICANCE: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.


Assuntos
Comportamento Animal , Aves/anatomia & histologia , Dinossauros , Fósseis , Animais , Aves/fisiologia
11.
Int Psychogeriatr ; 21(4): 672-87, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19470201

RESUMO

BACKGROUND: The Australian Imaging, Biomarkers and Lifestyle (AIBL) flagship study of aging aimed to recruit 1000 individuals aged over 60 to assist with prospective research into Alzheimer's disease (AD). This paper describes the recruitment of the cohort and gives information about the study methodology, baseline demography, diagnoses, medical comorbidities, medication use, and cognitive function of the participants. METHODS: Volunteers underwent a screening interview, had comprehensive cognitive testing, gave 80 ml of blood, and completed health and lifestyle questionnaires. One quarter of the sample also underwent amyloid PET brain imaging with Pittsburgh compound B (PiB PET) and MRI brain imaging, and a subgroup of 10% had ActiGraph activity monitoring and body composition scanning. RESULTS: A total of 1166 volunteers were recruited, 54 of whom were excluded from further study due to comorbid disorders which could affect cognition or because of withdrawal of consent. Participants with AD (211) had neuropsychological profiles which were consistent with AD, and were more impaired than participants with mild cognitive impairment (133) or healthy controls (768), who performed within expected norms for age on neuropsychological testing. PiB PET scans were performed on 287 participants, 100 had DEXA scans and 91 participated in ActiGraph monitoring. CONCLUSION: The participants comprising the AIBL cohort represent a group of highly motivated and well-characterized individuals who represent a unique resource for the study of AD. They will be reassessed at 18-month intervals in order to determine the predictive utility of various biomarkers, cognitive parameters and lifestyle factors as indicators of AD, and as predictors of future cognitive decline.


Assuntos
Doença de Alzheimer/diagnóstico , Biomarcadores/sangue , Encéfalo/patologia , Transtornos Cognitivos/diagnóstico , Estilo de Vida , Estudos Longitudinais , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Seleção de Pacientes , Tomografia por Emissão de Pósitrons , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Austrália , Transtornos Cognitivos/sangue , Transtornos Cognitivos/genética , Estudos de Coortes , Feminino , Humanos , Masculino , Programas de Rastreamento , Entrevista Psiquiátrica Padronizada/estatística & dados numéricos , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Psicometria , Valores de Referência , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA