Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 184
Filtrar
1.
Nature ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862026

RESUMO

Human spaceflight has historically been managed by government agencies, such as the NASA Twins Study1, but new commercial spaceflight opportunities have opened spaceflight to a broader population. In 2021, the SpaceX Inspiration4 mission launched the first-ever all civilian crew to low Earth orbit, which included the youngest American astronaut (age 29), novel in-flight experimental technologies (handheld ultrasound imaging, smartwatch wearables, and immune profiling), ocular alignment measurements, and new protocols for in-depth, multi-omic molecular and cellular profiling. Here we report the primary findings from the 3-day spaceflight mission, which induced a broad range of physiological and stress responses, neurovestibular changes indexed by ocular misalignment, and altered neurocognitive functioning, some of which match long-term spaceflight2, but almost all of which did not differ from baseline (pre-flight) after return to Earth. Overall, these preliminary civilian spaceflight data suggest that short-duration missions do not pose a significant health risk, and moreover present a rich opportunity to measure the earliest phases of adaptation to spaceflight in the human body at anatomical, cellular, physiologic, and cognitive levels. Finally, these methods and results lay the foundation for an open, rapidly expanding biomedical database for astronauts3, which can inform countermeasure development for both private and government-sponsored space missions.

2.
Ann R Coll Surg Engl ; 106(1): 19-28, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36927080

RESUMO

INTRODUCTION: Outcomes following pancreas transplantation are suboptimal and better donor selection is required to improve this. Vasoactive drugs (VaD) are commonly used to correct the abnormal haemodynamics of organ donors in intensive care units. VaDs can differentially affect insulin secretion positively (dobutamine) or negatively (noradrenaline). The hypothesis was that some VaDs might induce beta-cell stress or rest and therefore impact pancreas transplant outcomes. The aim of the study was to assess relationships between VaD use and pancreas transplant graft survival. METHODS: Data from the UK Transplant Registry on all pancreas transplants performed between 2004 and 2016 with complete follow-up data were included. Univariable- and multivariable-adjusted Cox regression analyses determined risks of graft failure associated with VaD use. RESULTS: In 2,183 pancreas transplants, VaDs were used in the following numbers of donors: dobutamine 76 (3.5%), dopamine 84 (3.8%), adrenaline 161 (7.4%), noradrenaline 1,589 (72.8%) and vasopressin 1,219 (55.8%). In multivariable models, adjusted for covariates and the co-administration of other VaDs, noradrenaline use (vs non-use) was a strong predictor of better graft survival (hazard ratio [95% confidence interval] 0.77 [0.64-0.94], p = 0.01). CONCLUSIONS: Noradrenaline use was associated with better graft survival in models adjusted for donor and recipient variables - this may be related to inhibition of pancreatic insulin secretion initiating pancreatic beta-cell 'rest'. Further research is required to replicate these findings and establish whether relationships are causal. Identification of alternative methods of inducing beta-cell rest could be valuable in improving graft outcomes.


Assuntos
Transplante de Pâncreas , Humanos , Transplante de Pâncreas/métodos , Norepinefrina/uso terapêutico , Dobutamina , Resultado do Tratamento , Doadores de Tecidos , Aloenxertos , Sobrevivência de Enxerto
3.
Nat Commun ; 14(1): 7407, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973799

RESUMO

The excitation of quasi-particles near the extrema of the electronic band structure is a gateway to electronic phase transitions in condensed matter. In a many-body system, quasi-particle dynamics are strongly influenced by the electronic single-particle structure and have been extensively studied in the weak optical excitation regime. Yet, under strong optical excitation, where light fields coherently drive carriers, the dynamics of many-body interactions that can lead to new quantum phases remain largely unresolved. Here, we induce such a highly non-equilibrium many-body state through strong optical excitation of charge carriers near the van Hove singularity in graphite. We investigate the system's evolution into a strongly-driven photo-excited state with attosecond soft X-ray core-level spectroscopy. We find an enhancement of the optical conductivity of nearly ten times the quantum conductivity and pinpoint it to carrier excitations in flat bands. This interaction regime is robust against carrier-carrier interaction with coherent optical phonons acting as an attractive force reminiscent of superconductivity. The strongly-driven non-equilibrium state is markedly different from the single-particle structure and macroscopic conductivity and is a consequence of the non-adiabatic many-body state.

4.
Integr Org Biol ; 5(1): obad008, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37035037

RESUMO

The increased use of imaging technology in biological research has drastically altered morphological studies in recent decades and allowed for the preservation of important collection specimens alongside detailed visualization of bony and soft-tissue structures. Despite the benefits associated with these newer imaging techniques, there remains a need for more "traditional" methods of morphological examination in many comparative studies. In this paper, we describe the costs and benefits of the various methods of visualizing, examining, and comparing morphological structures. There are significant differences not only in the costs associated with these different methods (monetary, time, equipment, and software), but also in the degree to which specimens are destroyed. We argue not for any one particular method over another in morphological studies, but instead suggest a combination of methods is useful not only for breadth of visualization, but also for the financial and time constraints often imposed on early-career research scientists.

5.
Integr Org Biol ; 4(1): obac013, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814192

RESUMO

Synopsis: Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, there are competing hypotheses (blowpipe vs. pressure tank hypothesis) of how archerfishes shoot and which oral structures are involved. Current understanding of archerfish shooting structures is largely based on two species, Toxotes chatareus and T. jaculatrix. We do not know if all archerfishes possess the same oral structures to shoot water, if anatomical variation is present within these oral structures, or how these features have evolved. Additionally, there is little information on the evolution of the Toxotidae as a whole, with all previous systematic works focusing on the interrelationships of the family. We first investigate the limits of archerfish species using new and previously published genetic data. Our analyses highlight that the current taxonomy of archerfishes does not conform to the relationships we recover. Toxotes mekongensis and T. siamensis are placed in the synonymy of T. chatareus, Toxotes carpentariensis is recognized as a species and removed from the synonymy of T. chatareus, and the genus Protoxotes is recognized for T. lorentzi based on the results of our analyses. We then take an integrative approach, using a combined analysis of discrete hard- and soft-tissue morphological characters with genetic data, to construct a phylogeny of the Toxotidae. Using the resulting phylogenetic hypothesis, we then characterize the evolutionary history and anatomical variation within the archerfishes. We discuss variation in the oral structures and the evolution of the mechanism with respect to the interrelationships of archerfishes, and find that the oral structures of archerfishes support the blowpipe hypothesis but soft-tissue oral structures may also play a role in shooting. Finally, by comparing the morphology of archerfishes to their sister group, we find that the Leptobramidae has relevant shooting features in the oral cavity, suggesting that some components of the archerfish shooting mechanism are examples of co-opted or exapted traits. Sinopsis Malay: Pelbagai jenis Ikan Sumpit (Toxotidae) dapat dijumpai di persekitaran air tawar dan payau di Asia Pasifik dan mereka terkenal dengan kebolehan mereka menembak air ke arah mangsa di darat. Tembakan air ini bertujuan untuk menyerang mangsa mereka dan menyebabkan mereka jatuh ke dalam air untuk ditangkap dan dimakan. Walaupun tingkah laku ini diketahui umum, terdapat hipotesis yang bersaing (hipotesis sumpitan vs. tangki tekanan) tentang cara ikan sumpit menembak dan struktur mulut yang terlibat. Pemahaman semasa tentang struktur menembak ikan sumpit adalah sebahagian besarnya berdasarkan dua spesies, Toxotes chatareus dan T. jaculatrix. Kami tidak pasti sama ada semua ikan sumpit mempunyai struktur mulut yang sama untuk menembak air, jika variasi anatomi terdapat dalam struktur mulut ini, atau bagaimana ciri-ciri ini telah berkembang. Tambahan pula, terdapat sedikit maklumat tentang evolusi Toxotidae secara keseluruhan, dengan semua penyelidikan sistematik sebelum ini memfokuskan pada hubungan saling keluarga. Kami pada mulanya mengkaji had spesies ikan sumpit ini menggunakan data genetik baharu dan yang diterbitkan sebelum ini. Analisis kami menunjukkan bahawa taksonomi semasa ikan sumpit tidak mematuhi hubungan yang kami perolehi. Toxotes mekongensis dan T. siamensis diletakkan bersama kesinoniman T. chatareus, Toxotes carpentariensis yang diiktiraf sebagai satu spesies dan dikeluarkan daripada kesinoniman T. chatareus, dan genus Protoxotes yang diiktiraf untuk T. lorentzi adalah berdasarkan hasil analisis kami. Kemudian kami mengambil pendekatan integratif, menggunakan analisis gabungan karakter morfologi tisu keras dan lembut diskret dengan data genetik, untuk membina filogeni Toxotidae. Menggunakan hipotesis filogenetik yang terhasil, kami kemudian mencirikan sejarah evolusi dan variasi anatomi dalam ikan sumpit. Kami membincangkan variasi dalam struktur mulut dan evolusi mekanisme berkenaan yang berkaitan dengan ikan sumpit, dan mendapati bahawa struktur mulut ikan sumpit menyokong hipotesis sumpitan tetapi struktur mulut tisu lembut juga mungkin memainkan peranan dalam cara menembak. Akhir sekali, dengan membandingkan morfologi ikan sumpit kepada kumpulan saudara mereka, kami mendapati bahawa Leptobramidae mempunyai ciri penangkapan yang relevan dalam rongga mulut mereka, menunjukkan bahawa beberapa komponen mekanisme penangkapan ikan sumpit merupakan contoh ciri-ciri yang diikut-sertakan atau diguna semula.

6.
Transplant Rev (Orlando) ; 36(2): 100692, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35364360

RESUMO

Pancreas transplantation (PT) allows improved glycaemic control for patients with complicated type 1 diabetes mellitus and is most commonly performed simultaneously with a renal transplant. Imaging modalities are critical for the assessment of pancreatic graft dysfunction, as clinical assessment and hyperglycaemia lack robust sensitivity for the transplant clinician. Biopsy represents the most conclusive standard of PT graft assessment but is challenging due to its invasive nature and the potential morbidity associated with the procedure. Innovative imaging technologies offer the opportunity to apply these modalities to improve PT outcomes while using non-invasive technologies to provide a diagnostic sensitivity that traditionally only biopsies can provide. Early graft dysfunction has traditionally been investigated with Computed tomography (CT) and ultrasound (US) scans. We explore adjuncts to these modalities including the application of contrast enhanced ultrasound (CEUS) for routine post-operative graft assessment to inform post-operative treatment strategies. There is currently a dearth of imaging modalities to reliably monitor long term graft function, but the use of innovative functional imaging techniques and how they can be applied to PT is discussed. Perfusion CT and glucose stimulated magnetic resonance imaging (MRI) to detect whole organ function are examined. In addition, early phase developments in beta-cell specific imaging methods to quantify beta-cell mass longitudinally are described. The clinical applications of such tools including Mn2+-enhanced MR and GLP-1R targeted PET/CT are reviewed and may demonstrate opportunities to provide the transplant clinician with greater information to support improved patient care.


Assuntos
Transplante de Rim , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Aloenxertos/diagnóstico por imagem , Humanos , Transplante de Rim/métodos , Pâncreas/patologia , Ultrassonografia/métodos
7.
Proc Biol Sci ; 288(1960): 20211436, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34641728

RESUMO

Tooth replacement rates of polyphyodont cartilaginous and bony fishes are hard to determine because of a lack of obvious patterning and maintaining specimens long enough to observe replacement. Pulse-chase is a fluorescent technique that differentially colours developing mineralized tissue. We present in situ tooth replacement rate and position data for the oral and pharyngeal detentions of Ophiodon elongatus (Pacific lingcod). We assessed over 10 000 teeth, in 20 fish, and found a daily replacement rate of about two teeth (3.6% of the dentition). The average tooth is in the dental battery for 27 days. The replacement was higher in the lower pharyngeal jaw (LPJ). We found no difference between replacement rates of feeding and non-feeding fish, suggesting feeding was not a driver of tooth replacement. Lingcod teeth have both a size and location fate; smaller teeth at one spot will not grow into larger teeth, even if a large tooth nearby is lost. We also found increased rates of replacement at the posterior of the LPJ relative to the anterior. We propose that lingcod teeth do not migrate in the jaw as they develop; their teeth are fated in size and location, erupting in their functional position.


Assuntos
Perciformes , Dente , Animais , Dentição , Arcada Osseodentária , Odontogênese
8.
Front Zool ; 18(1): 16, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863343

RESUMO

We tested the hypothesis that deep-sea fishes have poorly mineralized bone relative to shallower-dwelling species using data from a single family that spans a large depth range. The family Liparidae (snailfishes, Cottiformes) has representatives across the entire habitable depth range for bony fishes (0 m-> 8000 m), making them an ideal model for studying depth-related trends in a confined phylogeny. We used micro-computed tomography (micro-CT) scanning to test three aspects of skeletal reduction in snailfishes (50 species) across a full range of habitat depths: 1) reduction of structural dimensions, 2) loss of skeletal elements, and 3) reduction in bone density. Using depth data from the literature, we found that with increasing depth, the length of the dentary, neurocranium, and suborbital bones decreases. The ventral suction disk decreases width with increasing maximum habitat depth and is lost entirely in some deeper-living taxa, though not all. Although visual declines in bone density in deeper-living taxa were evident across full skeletons, individual densities of the lower jaw, vertebra, suction disk, hypural plate, and otoliths did not significantly decline with any depth metric. However, pelagic and polar taxa tended to show lower density bones compared to other species in the family. We propose that skeletal reductions allow snailfishes to maintain neutral buoyancy at great depths in the water column, while supporting efficient feeding and locomotion strategies. These findings suggest that changes in skeletal structure are non-linear and are driven not only by hydrostatic pressure, but by other environmental factors and by evolutionary ancestry, calling the existing paradigm into question.

9.
J R Soc Interface ; 17(169): 20200301, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32781934

RESUMO

Biological armours are potent model systems for understanding the complex series of competing demands on protective exoskeletons; after all, armoured organisms are the product of millions of years of refined engineering under the harshest conditions. Fishes are no strangers to armour, with various types of armour plating common to the 400-500 Myr of evolution in both jawed and jawless fishes. Here, we focus on the poachers (Agonidae), a family of armoured fishes native to temperate waters of the Pacific rim. We examined armour morphology, body stiffness and swimming performance in the northern spearnose poacher (Agonopsis vulsa) over ontogeny. As juveniles, these fishes make frequent nocturnal forays into the water column in search of food, while heavily armoured adults are bound to the benthos. Most armour dimensions and density increase with body length, as does body stiffness. Juvenile poachers have enlarged spines on their armour whereas adults invest more mineral in armour plate bases. Adults are stiffer and accelerate faster than juveniles with an anguilliform swimming mode. Subadults more closely approximate adults more than smaller juveniles, with regards to both swimming and armour mechanics. Poacher armour serves multiple functions over ontogeny, from facilitating locomotion, slowing sinking and providing defence.


Assuntos
Perciformes , Natação , Animais , Peixes , Locomoção , Modelos Biológicos
10.
Integr Org Biol ; 2(1): obaa009, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33791553

RESUMO

The decreasing cost of acquiring computed tomographic (CT) data has fueled a global effort to digitize the anatomy of museum specimens. This effort has produced a wealth of open access digital three-dimensional (3D) models of anatomy available to anyone with access to the Internet. The potential applications of these data are broad, ranging from 3D printing for purely educational purposes to the development of highly advanced biomechanical models of anatomical structures. However, while virtually anyone can access these digital data, relatively few have the training to easily derive a desirable product (e.g., a 3D visualization of an anatomical structure) from them. Here, we present a workflow based on free, open source, cross-platform software for processing CT data. We provide step-by-step instructions that start with acquiring CT data from a new reconstruction or an open access repository, and progress through visualizing, measuring, landmarking, and constructing digital 3D models of anatomical structures. We also include instructions for digital dissection, data reduction, and exporting data for use in downstream applications such as 3D printing. Finally, we provide Supplementary Videos and workflows that demonstrate how the workflow facilitates five specific applications: measuring functional traits associated with feeding, digitally isolating anatomical structures, isolating regions of interest using semi-automated segmentation, collecting data with simple visual tools, and reducing file size and converting file type of a 3D model.


PORTUGUÊS (PORTUGUESE)  O Guia da Galáxia da Tomografia Computadorizada para um Biólogo: instruções passo a passo para preparar e analisar dados tomográficos usando um software gratuito de acesso aberto  Thaddaeus J. Buser, Olivia F. Boyd, Álvaro Cortés, Cassandra M. Donatelli, Matthew A. Kolmann, Jennifer L. Luparell, Janne A. Pfeiffenberger, Brian L. Sidlauskas, Adam P. Summers  RESUMOO custo decrescente da obtenção de dados de Tomografia Computadorizada (TC) alimentou um esforço global para digitalizar espécimes depositados em museus. Esse esforço produziu uma grande variedade de modelos digitais 3 D com dados de anatomia, disponíveis para qualquer pessoa com acesso à Internet. As aplicações potenciais desses dados são amplas, desde a impressão 3 D para fins puramente educacionais, até o desenvolvimento de modelos biomecânicos de estruturas anatômicas altamente avançados. No entanto, enquanto praticamente qualquer pessoa pode acessar esses dados digitais, relativamente poucos têm o treinamento para obter facilmente um produto de interesse (por exemplo, uma visualização 3 D de uma estrutura anatômica). Aqui, apresentamos um tutorial baseado em um software gratuito de código aberto e multiplataforma para o processamento de dados de TC. Fornecemos instruções passo a passo que começam com a obtenção de dados de TC a partir de uma nova reconstrução ou num repositório de acesso aberto, e progredimos através da visualização, medição, marca de referência e construção de modelos digitais 3 D de estruturas anatômicas. Também incluímos instruções para dissecação digital, redução de dados e exportação de dados para uso em aplicativos posteriores, como os de impressoras 3 D. Por fim, fornecemos vídeos e tutoriais suplementares que demonstram como o tutorial facilita cinco aplicações específicas: medir características funcionais associadas à alimentação, isolar estruturas anatômicas digitalmente, isolar regiões de interesse usando segmentação semi-automática, coletar dados com ferramentas visuais simples, e reduzir o tamanho de arquivo e converter o tipo de arquivo do modelo 3 D.


FRANÇAIS (FRENCH)  Guide de l'historien de la nature à travers la galaxie TDM: instructions étape par étape pour la préparation et l'analyse de données tomodensitométrique (TDM) à l'aide d'un logiciel à accès ouvert multiplateforme Thaddaeus J. Buser, Olivia F. Boyd, Álvaro Cortés, Cassandra M. Donatelli, Matthew A. Kolmann, Jennifer L. Luparell, Janne A. Pfeiffenberger, Brian L. Sidlauskas, Adam P. Summers RÉSUMÉLe coût décroissant de l'acquisition de données tomodensitométriques (TDM) a alimenté un effort mondial pour numériser l'anatomie des spécimens de musée. Cet effort a produit une multitude de modèles d'anatomie numérique 3 D en accès libre accessibles à tous ceux qui ont accès à Internet. Les applications potentielles de ces données sont vastes, allant de l'impression 3 D à des fins purement pédagogiques au développement de modèles biomécaniques de structures anatomiques très avancés. Cependant, alors que pratiquement tout le monde peut accéder à ces données numériques, relativement peu ont la formation nécessaire pour en tirer facilement un produit intéressant (par exemple, une visualisation 3 D d'une structure anatomique). Ici, nous présentons un flux de travail basé sur un logiciel gratuit, à accès ouvert et multiplateforme pour le traitement des données TDM. Nous fournissons des instructions étape par étape qui commencent par l'acquisition de données TDM à partir d'une nouvelle reconstruction ou d'un référentiel en accès gratuit, et progressent à travers la visualisation, la mesure, le marquage et la construction de modèles numériques 3 D de structures anatomiques. Nous incluons également des instructions pour la dissection numérique, la réduction des données et l'exportation de données à utiliser dans des applications en aval telles que l'impression 3 D. Enfin, nous proposons des vidéos et des workflows supplémentaires qui montrent comment le workflow facilite cinq applications spécifiques: mesurer les traits fonctionnels associés à l'alimentation, isoler numériquement les structures anatomiques, isoler les régions d'intérêt à l'aide de la segmentation semi-automatisée, collecter des données avec des outils visuels simples, réduire la taille du fichier et convertir le type de fichierd'un modèle 3 D.

12.
Integr Comp Biol ; 59(2): 394-409, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31004486

RESUMO

Suction feeding and gill ventilation in teleosts are functionally coupled, meaning that there is an overlap in the structures involved with both functions. Functional coupling is one type of morphological integration, a term that broadly refers to any covariation, correlation, or coordination among structures. Suction feeding and gill ventilation exhibit other types of morphological integration, including functional coordination (a tendency of structures to work together to perform a function) and evolutionary integration (a tendency of structures to covary in size or shape across evolutionary history). Functional coupling, functional coordination, and evolutionary integration have each been proposed to limit morphological diversification to some extent. Yet teleosts show extraordinary cranial diversity, suggesting that there are mechanisms within some teleost clades that promote morphological diversification, even within the highly integrated suction feeding and gill ventilatory systems. To investigate this, we quantified evolutionary integration among four mechanical units associated with suction feeding and gill ventilation in a diverse clade of benthic, primarily suction-feeding fishes (Cottoidei; sculpins and relatives). We reconstructed cottoid phylogeny using molecular data from 108 species, and obtained 24 linear measurements of four mechanical units (jaws, hyoid, opercular bones, and branchiostegal rays) from micro-CT reconstructions of 44 cottoids and 1 outgroup taxon. We tested for evolutionary correlation and covariation among the four mechanical units using phylogenetically corrected principal component analysis to reduce the dimensionality of measurements for each unit, followed by correlating phylogenetically independent contrasts and computing phylogenetic generalized least squares models from the first principle component axis of each of the four mechanical units. The jaws, opercular bones, and branchiostegal rays show evolutionary integration, but the hyoid is not positively integrated with these units. To examine these results in an ecomorphological context, we used published ecological data in phylogenetic ANOVA models to demonstrate that the jaw is larger in fishes that eat elusive or grasping prey (e.g., prey that can easily escape or cling to the substrate) and that the hyoid is smaller in intertidal and hypoxia-tolerant sculpins. Within Cottoidei, the relatively independent evolution of the hyoid likely has reduced limitations on morphological evolution within the highly morphologically integrated suction feeding and gill ventilatory systems.


Assuntos
Comportamento Alimentar , Brânquias/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Perciformes/fisiologia , Animais , Evolução Biológica , Fenômenos Biomecânicos , Brânquias/fisiologia , Arcada Osseodentária/fisiologia , Perciformes/anatomia & histologia , Filogenia , Respiração , Crânio/anatomia & histologia , Sucção
13.
Br J Surg ; 106(3): 174-180, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30667536

RESUMO

BACKGROUND: Normothermic regional perfusion (NRP) is a novel technique that aids organ recovery from donors after circulatory death (DCDs). However, ethical concerns exist regarding the potential return of spontaneous cerebral and cardiac activity (ROSCCA). This study aimed to determine the likelihood of ROSCCA in NRP-DCDs of abdominal organs. METHODS: Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory out-of-hospital cardiac arrest (OOHCA) was identified as a comparator for NRP-DCDs and as a validation cohort. A systematic search identified all articles relating to NRP-DCDs and ECPR-OOHCA. Rates of ROSCCA and survival outcomes (ECPR-OOHCA only) were recorded and analysed according to the duration of no perfusion. RESULTS: In NRP-DCDs, 12 of 410 articles identified by database searching were eligible for inclusion. There were no instances of ROSCCA recorded among 493 donors. In ECPR-OOHCA, eight of 947 screened articles were eligible for inclusion (254 patients). Where the absence of perfusion exceeded 5 min in ECPR-OOHCA, there were no survivors with a favourable neurological outcome. CONCLUSION: ROSCCA is unlikely following commencement of NRP and has not occurred to date. Strict observance of the 5-min interval following asystole provides satisfactory assurance that ROSCCA will not occur following NRP.


Assuntos
Encéfalo/fisiologia , Coração/fisiologia , Reperfusão/métodos , Doadores de Tecidos , Coleta de Tecidos e Órgãos/métodos , Adolescente , Adulto , Idoso , Reanimação Cardiopulmonar/métodos , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Pessoa de Meia-Idade , Parada Cardíaca Extra-Hospitalar/fisiopatologia , Parada Cardíaca Extra-Hospitalar/terapia , Fluxo Sanguíneo Regional/fisiologia , Adulto Jovem
14.
Integr Org Biol ; 1(1): obz023, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33791537

RESUMO

Evolutionary transitions between habitats have been catalysts for some of the most stunning examples of adaptive diversification, with novel niches and new resources providing ecological opportunity for such radiations. In aquatic animals, transitions from saltwater to freshwater habitats are rare, but occur often enough that in the Neotropics for example, marine-derived fishes contribute noticeably to regional ichthyofaunal diversity. Here, we investigate how morphology has evolved in a group of temperate fishes that contain a marine to freshwater transition: the sculpins (Percomorpha; Cottoidea). We devised a novel method for classifying dietary niche and relating functional aspects of prey to their predators. Coupled with functional measurements of the jaw apparatus in cottoids, we explored whether freshwater sculpins have fundamentally changed their niche after invading freshwater (niche lability) or if they retain a niche similar to their marine cousins (niche conservatism). Freshwater sculpins exhibit both phylogeographical and ecological signals of phylogenetic niche conservatism, meaning that regardless of habitat, sculpins fill similar niche roles in either saltwater or freshwater. Rather than competition guiding niche conservatism in freshwater cottoids, we argue that strong intrinsic constraints on morphological and ecological evolution are at play, contra to other studies of diversification in marine-derived freshwater fishes. However, several intertidal and subtidal sculpins as well as several pelagic freshwater species from Lake Baikal show remarkable departures from the typical sculpin bauplan. Our method of prey categorization provides an explicit, quantitative means of classifying dietary niche for macroevolutionary studies, rather than relying on somewhat arbitrary means used in previous literature.


Tem Nicho, Viaja. Novos Meios de Associar Dieta e Ecomorfologia Revelam Conservadorismo de Nicho em Peixes Cotoides de Água Doce (Have Niche, Will Travel. New Means of Linking Diet and Ecomorphology Reveals Niche Conservatism in Freshwater Cottoid Fishes) Transições evolutivas entre habitats têm sido catalisadores de alguns dos mais impressionantes exemplos de diversificação adaptativa, com novos nichos e recursos proporcionando oportunidade ecológica para tais radiações. Em animais aquáticos, as transições de água salgada para habitats de água doce são raras, mas ocorrem com freqüência suficiente para que, nos Neotrópicos, por exemplo, os peixes marinhos contribuam notavelmente para a diversidade regional da ictiofauna. Aqui, nós investigamos como a morfologia evoluiu em um grupo de peixes temperados que contêm uma transição marinha para a água doce: os esculpentes (Percomorpha; Cottoidea). Nós concebemos um novo método para classificar o nicho alimentar e relacionar os aspectos funcionais das presas aos seus predadores. Juntamente com medidas funcionais do aparato de mandíbula em cotoides, exploramos se os esculpentes de água doce mudaram fundamentalmente seu nicho depois de invadi-la (labilidade de nicho) ou se eles mantêm um nicho semelhante aos seus primos marinhos (conservadorismo de nicho). Os esculpentes de água doce exibem sinais filogeográficos e ecológicos de conservadorismo filogenético de nicho, o que significa que, independente do habitat, os esculpentes preenchem papéis ecológicos semelhantes em água salgada ou doce. Mais do que a concorrência guiando o conservadorismo de nicho em cotoides de água doce, argumentamos que fortes restrições intrínsecas à evolução morfológica e ecológica estão em jogo, em contraste com outros estudos de diversificação em peixes de água doce derivados do mar. No entanto, vários esculpentes intertidais e subtidais, bem como várias espécies pelágicas de água doce do Lago Baikal, mostram notáveis desvios do típico bauplan dos esculpentes. Nosso método de categorização de presas fornece um modo explícito e quantitativo de classificar o nicho alimentar para estudos macroevolutivos ao invéz de depender de meios arbitrários usados na literatura anterior. Translated to Portuguese by G. Sobral (gabisobral@gmail.com).

15.
Zoology (Jena) ; 130: 19-29, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30502835

RESUMO

Video-based observations of voluntary movements reveal that six species of pleuronectid flatfishes use sequential portions of long-based dorsal and anal fins as "feet" (hereafter, fin-feet) to move on the substrate. All six species used a gait that we term "walking," which produced constant forward movement, and several of these species also used a second gait that we call "bounding" for intermittent movements over the substrate. We selected Pacific Sand Sole, Psettichthys melanostictus, and English Sole, Parophrys vetulus, for kinematic analyses of these two gaits. Psettichthys melanostictus consistently used walking for benthic locomotion; Parophrys vetulus primarily used a bounding gait. During forward walking, a fin ray swings up off the substrate, protracts and converges with neighboring fin rays to contribute to a fin-foot. The fin-foot pushes down on the substrate and rotates posteriorly by sequential recruitment of fin rays, a pattern known as a metachronal wave. As one fin-foot passes off the posterior end of the fin, a new fin-foot forms anteriorly. During bounding, undulations of the body and tail assist one or two waves of fin-feet, producing rapid but intermittent forward acceleration of the body. Flatfishes also use fin-feet to maneuver on the substrate. The Starry Flounder, Platichthys stellatus, performs near zero displacement rotation by running waves of fin-feet in opposing directions along the dorsal and anal fins. Although other teleosts use specialized pectoral fin rays for bottom walking (e.g., Sea Robins: Triglidae), the duplication of structures and patterns of movement in the median fins of flatfishes more closely resembles metachronal motions of millipede feet or the parapodia of polychaete worms. Sequential use of median fin rays in flatfishes resembles that of other teleosts that swim with elongate median fins, including Amiiformes, Gymnotiformes, and some Tetraodontiformes, but flatfishes offer a novel form of substrate locomotion based on dorsal and anal fins.


Assuntos
Linguados/fisiologia , Atividade Motora/fisiologia , Animais , Fenômenos Biomecânicos , Natação
16.
Can Commun Dis Rep ; 44(12): 309-316, 2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31517953

RESUMO

BACKGROUND: In 2017, a mumps outbreak was identified in a cohort of 18-34 year olds in Toronto, Canada. OBJECTIVE: To describe a large community mumps outbreak in an urban centre from January 2017 to February 2018 among young adults. METHODS: A broad range of interventions were implemented in an attempt to reach the target audience; including case and contact management, vaccination clinics at schools and clinicians' offices, school exclusions, bar inspections, traditional communication strategies (including health care provider updates and posters) and newer communication strategies (including three sequential social media campaigns). RESULTS: A total of 143 cases of mumps were identified. Although cases' ages ranged from three to 72 years, most (76%) were 18-34 year olds, many of whom had frequented bars and local food establishments in downtown Toronto. 84% (n=120) of the cases were community-acquired. Only 16% (n=23) of the cases reported exposures in schools and post-secondary school institutions. Of those, 39% (n=56) of cases had an unknown vaccination history; 34% (n=49) were either not vaccinated or partially vaccinated with one dose of measles-mumps-rubella vaccine; and 27% (n=38) had received the recommended two doses of mumps vaccine. Determining vaccination status was a challenge, in part due to the lack of a registry. Vaccination was recommended when subjects were known to have had fewer than two doses of vaccine or had an unknown vaccination status. A social media campaign, emphasizing the risk of social activities if not protected from the mumps, yielded over 500,000 impressions from Facebook and Twitter messages and ads and an impressive engagement rate of between 1% and 10x%. CONCLUSION: This was the largest mumps outbreak in Toronto in over 20 years. Among young adults, ongoing social media and traditional communication campaigns can contribute to the control of community mumps outbreaks. Encouraging vaccine uptake is desirable, but without a vaccine registry it is difficult to assess vaccination coverage among adults. Susceptible cohorts of young adults who were not adequately vaccinated pose a risk for future outbreaks. Given that almost 30% of the mumps cases were fully vaccinated with two doses of mumps-containing vaccine, even two doses may not provide complete protection.

17.
J Perinatol ; 38(1): 64-70, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29120456

RESUMO

OBJECTIVE: The objective of this study was to determine the skin barrier changes during postnatal month 1 among infants receiving routine mustard oil massage in the humid conditions of rural Nepal. STUDY DESIGN: This was an observational study among 500 live-born neonates receiving mustard oil massage. Skin integrity such as erythema, rash, dryness, skin pH, stratum corneum protein concentration and transepidermal water loss was measured on days 1, 3, 7, 14 and 28. RESULTS: Erythema and rash increased (worsened) during weeks 1 and 2, then decreased over weeks 3 and 4. Skin pH (6.1±0.5 to 5.0±0.6) and stratum corneum protein (16.6±7.9 to 13.5±5.9 µg cm-2) decreased. Transepidermal water loss increased from 33.2±23.5 to 43.0±24.5 g m-2 h-1 at day 28. Skin pH and stratum corneum protein were higher for early versus late premature infants. CONCLUSION: Premature and full-term skin condition was generally poor especially during the first 2 weeks, improving thereafter. Maturational changes were evident.


Assuntos
Epiderme/metabolismo , Eritema/fisiopatologia , Massagem/métodos , Mostardeira/efeitos adversos , Óleos de Plantas/efeitos adversos , Perda Insensível de Água/fisiologia , Administração Tópica , Emolientes/efeitos adversos , Feminino , Proteínas Filagrinas , Idade Gestacional , Humanos , Concentração de Íons de Hidrogênio , Recém-Nascido , Proteínas de Filamentos Intermediários/análise , Masculino , Nepal , Ensaios Clínicos Controlados Aleatórios como Assunto , População Rural
18.
Curr Biol ; 27(10): R371-R375, 2017 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-28535384

RESUMO

Invertebrate biomechanics focuses on mechanical analyses of non-vertebrate animals, which at root is no different in aim and technique from vertebrate biomechanics, or for that matter the biomechanics of plants and fungi. But invertebrates are special - they are fabulously diverse in form, habitat, and ecology and manage this without the use of hard, internal skeletons. They are also numerous and, in many cases, tractable in an experimental and field setting. In this Primer, we will probe three axes of invertebrate diversity: worms (Phylum Annelida), spiders (Class Arachnida) and insects (Class Insecta); three habitats: subterranean, terrestrial and airborne; and three integrations with other fields: ecology, engineering and evolution. Our goal is to capture the field of invertebrate biomechanics, which has blossomed from having a primary focus on discoveries at the interface of physics and biology to being inextricably linked with integrative challenges that span biology, physics, mathematics and engineering.


Assuntos
Ecologia , Ecossistema , Invertebrados/fisiologia , Animais , Fenômenos Biomecânicos , Invertebrados/classificação , Filogenia
19.
J Med Entomol ; 54(4): 980-984, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28399282

RESUMO

Horn fly, Haematobia irritans (L.), population estimates often serve as a diagnostic tool prior to implementing managerial control options available to researchers and producers. Digital photographs taken of cattle infested with horn flies have been suggested to provide similarly accurate population estimates as compared with traditional visual assessments. The objective of this study was to compare visual and digital techniques used to estimate horn fly populations. Sixteen Angus × Hereford yearling heifers artificially infested with four levels of horn flies (Low = 0 flies; Medium = 250 flies; High = 500 flies; Extreme = 1,000 flies) were evaluated. Population estimates were taken visually by experienced (VE1) and inexperienced (VE2) technicians, as well as digitally, with photographs taken on both lateral sides of the south-facing animal. Horn flies were counted in both photographs and combined (CDC) for full body estimates. In addition, the highest photographed side population times two (DDC) was used for comparison. Estimations were made at 0700, 1200, and 1900 h the day following infestation. A time of observation × infestation level interaction (P < 0.01) was detected. On average, VE1 population estimates were greater (P < 0.01) than any other counting method observed. Morning estimates were greater (P < 0.05) than those taken at noon or in the early evening regardless of counting method. Further research regarding the standardization of these techniques to ensure more accurate population estimates is needed before these methods can be incorporated into integrated pest management programs.


Assuntos
Entomologia/métodos , Muscidae/fisiologia , Parasitologia/métodos , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Ectoparasitoses/parasitologia , Ectoparasitoses/veterinária , Feminino , Fotografação/veterinária , Densidade Demográfica
20.
J Anim Sci ; 95(12): 5629-5636, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29293800

RESUMO

Data collected for 10 or more years at the West Central Research and Extension Center, North Platte, NE ( = 1,104); the Gudmundsen Sandhills Laboratory, Whitman, NE ( = 1,333); and the USDA, ARS, Fort Keogh Livestock and Range Research Laboratory, Miles City, MT ( = 1,176) were retrospectively analyzed to evaluate growth and reproductive performance of beef heifers classified by pubertal status before first breeding. Concentrations of progesterone in serum from 2 blood samples collected 9 to 11 d apart before the breeding season classified heifers as pubertal (progesterone ≥ 1.0 ng/mL in 1 or both samples) or nonpubertal (progesterone < 1.0 ng/mL in both samples). Average date of birth was earlier ( < 0.06) and proportion born in the first 21 d of the calving season was 10 to 20 percentage points greater for heifers that were pubertal at the start of breeding compared with heifers not pubertal by the start of breeding. Heifers that were pubertal by the start of breeding were 7 to 10 kg heavier ( < 0.01) and 1 cm taller ( < 0.01) at weaning than heifers not pubertal by the start of breeding. Differences in BW persisted through the start of breeding to pregnancy diagnosis. Heifers that achieved puberty by the start of breeding had greater ( < 0.05) feed intake and G:F during postweaning development and had greater ( < 0.01) LM area and fat thickness over the LM at approximately 1 yr of age compared with heifers not pubertal by the start of breeding. Heifers that achieved puberty before the start of breeding had greater ( < 0.01) ADG from birth to weaning but slower ( < 0.10) rates of gain from the start of breeding through pregnancy diagnosis. Pregnancy rate was greater ( < 0.01) for heifers that were pubertal at the start of breeding. In heifers that became pregnant, those that were pubertal before the start of breeding calved earlier ( < 0.01), with a greater ( < 0.01) percentage calving in the first 21 d of calving than heifers not pubertal at the start of breeding. Calves from heifers that achieved puberty before the start of breeding were heavier at weaning ( < 0.01) than calves from heifers that had not achieved puberty by the start of breeding. In summary, heifers that failed to achieve puberty by the start of breeding were less desirable for several traits evaluated. Based on these results, implementing feeding strategies to increase the proportion of heifers that achieve puberty before first breeding could result in propagation of undesirable characteristics.


Assuntos
Bovinos/fisiologia , Reprodução , Maturidade Sexual , Animais , Cruzamento , Bovinos/crescimento & desenvolvimento , Feminino , Parto , Gravidez , Taxa de Gravidez , Estações do Ano , Desmame
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...