RESUMO
Multilevel interventions (MLIs) are appropriate to reduce health disparities among Indigenous peoples because of their ability to address these communities' diverse histories, dynamics, cultures, politics, and environments. Intervention science has highlighted the importance of context-sensitive MLIs in Indigenous communities that can prioritize Indigenous and local knowledge systems and emphasize the collective versus the individual. This paradigm shift away from individual-level focus interventions to community-level focus interventions underscores the need for community engagement and diverse partnerships in MLI design, implementation, and evaluation. In this paper, we discuss three case studies addressing how Indigenous partners collaborated with researchers in each stage of the design, implementation, and evaluation of MLIs to reduce health disparities impacting their communities. We highlight the following: (1) collaborations with multiple, diverse tribal partners to carry out MLIs which require iterative, consistent conversations over time; (2) inclusion of qualitative and Indigenous research methods in MLIs as a way to honor Indigenous and local knowledge systems as well as a way to understand a health disparity phenomenon in a community; and (3) relationship building, maintenance, and mutual respect among MLI partners to reconcile past research abuses, prevent extractive research practices, decolonize research processes, and generate co-created knowledge between Indigenous and academic communities.
Assuntos
Disparidades nos Níveis de Saúde , Humanos , Povos Indígenas , Serviços de Saúde do Indígena/organização & administraçãoRESUMO
Evolutionary adaptation to novel, specialized modes of life is often associated with a close mapping of form to the new function, resulting in narrow morphological disparity. For bivalve molluscs, endolithy (rock-boring) has biomechanical requirements thought to diverge strongly from those of ancestral functions. However, endolithy in bivalves has originated at least eight times. Three-dimensional morphometric data representing 75 species from approximately 94% of extant endolithic genera and families, along with 310 non-endolithic species in those families, show that endolithy is evolutionarily accessible from many different morphological starting points. Although some endoliths appear to converge on certain shell morphologies, the range of endolith shell form is as broad as that belonging to any other bivalve substrate use. Nevertheless, endolithy is a taxon-poor function in Bivalvia today. This limited richness does not derive from origination within source clades having significantly low origination or high extinction rates, and today's endoliths are not confined to low-diversity biogeographic regions. Instead, endolithy may be limited by habitat availability. Both determinism (as reflected by convergence among distantly related taxa) and contingency (as reflected by the endoliths that remain close to the disparate morphologies of their source clades) underlie the occupation of endolith morphospace.
Assuntos
Evolução Biológica , Bivalves , Animais , Ecossistema , Adaptação Fisiológica , Aclimatação , FilogeniaRESUMO
Both the Cambrian explosion, more than half a billion years ago, and its Ordovician aftermath some 35 Myr later, are often framed as episodes of widespread ecological opportunity, but not all clades originating during this interval showed prolific rises in morphological or functional disparity. In a direct analysis of functional disparity, instead of the more commonly used proxy of morphological disparity, we find that ecological functions of Class Bivalvia arose concordantly with and even lagged behind taxonomic diversification, rather than the early-burst pattern expected for clades originating in supposedly open ecological landscapes. Unlike several other clades originating in the Cambrian explosion, the bivalves' belated acquisition of key anatomical novelties imposed a macroevolutionary lag, and even when those novelties evolved in the Early Ordovician, functional disparity never surpassed taxonomic diversity. Beyond this early period of animal evolution, the founding and subsequent diversification of new major clades and their functions might be expected to follow the pattern of the early bivalves-one where interactions between highly dynamic environmental and biotic landscapes and evolutionary contingencies need not promote prolific functional innovation.
Assuntos
Evolução Biológica , Bivalves , Animais , Fósseis , FilogeniaRESUMO
Modular evolution, the relatively independent evolution of body parts, may promote high morphological disparity in a clade. Conversely, integrated evolution via stronger covariation of parts may limit disparity. However, integration can also promote high disparity by channelling morphological evolution along lines of least resistance-a process that may be particularly important in the accumulation of disparity in the many invertebrate systems having accretionary growth. We use a time-calibrated phylogenetic hypothesis and high-density, three-dimensional semilandmarking to analyse the relationship between modularity, integration and disparity in the most diverse extant bivalve family: the Veneridae. In general, venerids have a simple, two-module parcellation of their body that is divided into features of the calcium carbonate shell and features of the internal soft anatomy. This division falls more along developmental than functional lines when placed in the context of bivalve anatomy and biomechanics. The venerid body is tightly integrated in absolute terms, but disparity appears to increase with modularity strength among subclades and ecologies. Thus, shifts towards more mosaic evolution beget higher morphological variance in this speciose family.
Assuntos
Evolução Biológica , Bivalves , Animais , Filogenia , Crânio/anatomia & histologiaRESUMO
Analyses of evolutionary dynamics depend on how phylogenetic data are time-scaled. Most analyses of extant taxa assume a purely bifurcating model, where nodes are calibrated using the daughter lineage with the older first occurrence in the fossil record. This contrasts with budding, where nodes are calibrated using the younger first occurrence. Here, we use the extensive fossil record of bivalve molluscs for a large-scale evaluation of how branching models affect macroevolutionary analyses. We time-calibrated 91% of nodes, ranging in age from 2.59 to 485 Ma, in a phylogeny of 97 extant bivalve families. Allowing budding-based calibrations minimizes conflict between the tree and observed fossil record, and reduces the summed duration of inferred 'ghost lineages' from 6.76 billion years (Gyr; bifurcating model) to 1.00 Gyr (budding). Adding 31 extinct paraphyletic families raises ghost lineage totals to 7.86 Gyr (bifurcating) and 1.92 Gyr (budding), but incorporates more information to date divergences between lineages. Macroevolutionary analyses under a bifurcating model conflict with other palaeontological evidence on the magnitude of the end-Palaeozoic extinction, and strongly reduce Cenozoic diversification. Consideration of different branching models is essential when node-calibrating phylogenies, and for a major clade with a robust fossil record, a budding model appears more appropriate.
Assuntos
Bivalves , Fósseis , Animais , Evolução Biológica , Bivalves/genética , Humanos , FilogeniaRESUMO
Altered function of the Gq-coupled, Group 1 metabotropic glutamate receptors, specifically mGlu5, is implicated in multiple mouse models of autism and intellectual disability. mGlu5 dysfunction has been most well characterized in the fragile X syndrome mouse model, the Fmr1 knock-out (KO) mouse, where pharmacological and genetic reduction of mGlu5 reverses many phenotypes. mGlu5 is less associated with its scaffolding protein Homer in Fmr1 KO mice, and restoration of mGlu5-Homer interactions by genetic deletion of a short, dominant negative of Homer, H1a, rescues many phenotypes of Fmr1 KO mice. These results suggested that disruption of mGlu5-Homer leads to phenotypes of FXS. To test this idea, we examined mice with a knockin mutation of mGlu5 (F1128R; mGlu5(R/R)) that abrogates binding to Homer. Although FMRP levels were normal, mGlu5(R/R) mice mimicked multiple phenotypes of Fmr1 KO mice, including reduced mGlu5 association with the postsynaptic density, enhanced constitutive mGlu5 signaling to protein synthesis, deficits in agonist-induced translational control, protein synthesis-independent LTD, neocortical hyperexcitability, audiogenic seizures, and altered behaviors, including anxiety and sensorimotor gating. These results reveal new roles for the Homer scaffolds in regulation of mGlu5 function and implicate a specific molecular mechanism in a complex brain disease. SIGNIFICANCE STATEMENT: Abnormal function of the metabotropic, or Gq-coupled, glutamate receptor 5 (mGlu5) has been implicated in neurodevelopmental disorders, including a genetic cause of intellectual disability and autism called fragile X syndrome. In brains of a mouse model of fragile X, mGlu5 is less associated with its binding partner Homer, a scaffolding protein that regulates mGlu5 localization to synapses and its ability to activate biochemical signaling pathways. Here we show that a mouse expressing a mutant mGlu5 that cannot bind to Homer is sufficient to mimic many of the biochemical, neurophysiological, and behavioral symptoms observed in the fragile X mouse. This work provides strong evidence that Homer-mGlu5 binding contributes to symptoms associated with neurodevelopmental disorders.
Assuntos
Proteínas de Transporte/genética , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/fisiopatologia , Receptor de Glutamato Metabotrópico 5/genética , Animais , Proteína do X Frágil da Deficiência Intelectual/genética , Técnicas de Introdução de Genes , Proteínas de Arcabouço Homer , Técnicas In Vitro , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neocórtex/metabolismo , Fenótipo , Convulsões/genética , Convulsões/fisiopatologia , Filtro SensorialRESUMO
BACKGROUND: The Activity-regulated cytoskeleton-associated protein, Arc, is an immediate-early gene product implicated in various forms of synaptic plasticity. Arc promotes endocytosis of AMPA type glutamate receptors and regulates cytoskeletal assembly in neuronal dendrites. Its role in endocytosis may be mediated by its reported interaction with dynamin 2, a 100 kDa GTPase that polymerizes around the necks of budding vesicles and catalyzes membrane scission. METHODS: Enzymatic and turbidity assays are used in this study to monitor effects of Arc on dynamin activity and polymerization. Arc oligomerization is measured using a combination of approaches, including size exclusion chromatography, sedimentation analysis, dynamic light scattering, fluorescence correlation spectroscopy, and electron microscopy. RESULTS: We present evidence that bacterially-expressed His6-Arc facilitates the polymerization of dynamin 2 and stimulates its GTPase activity under physiologic conditions (37°C and 100mM NaCl). At lower ionic strength Arc also stabilizes pre-formed dynamin 2 polymers against GTP-dependent disassembly, thereby prolonging assembly-dependent GTP hydrolysis catalyzed by dynamin 2. Arc also increases the GTPase activity of dynamin 3, an isoform of implicated in dendrite remodeling, but does not affect the activity of dynamin 1, a neuron-specific isoform involved in synaptic vesicle recycling. We further show in this study that Arc (either His6-tagged or untagged) has a tendency to form large soluble oligomers, which may function as a scaffold for dynamin assembly and activation. CONCLUSIONS AND GENERAL SIGNIFICANCE: The ability of Arc to enhance dynamin polymerization and GTPase activation may provide a mechanism to explain Arc-mediated endocytosis of AMPA receptors and the accompanying effects on synaptic plasticity.
Assuntos
Proteínas do Citoesqueleto/metabolismo , Dinaminas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Dinamina I/metabolismo , Dinamina II/metabolismo , Dinamina III/metabolismo , Dinaminas/química , Ativação Enzimática , Guanosina Trifosfato/metabolismo , Histidina/metabolismo , Humanos , Hidrólise , Camundongos , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Oligopeptídeos/metabolismo , Polimerização , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Cloreto de Sódio/química , Temperatura , Fatores de TempoRESUMO
Marine bivalves are important components of ecosystems and exploited by humans for food across the world, but the intrinsic vulnerability of exploited bivalve species to global changes is poorly known. Here, we expand the list of shallow-marine bivalves known to be exploited worldwide, with 720 exploited bivalve species added beyond the 81 in the United Nations FAO Production Database, and investigate their diversity, distribution and extinction vulnerability using a metric based on ecological traits and evolutionary history. The added species shift the richness hotspot of exploited species from the northeast Atlantic to the west Pacific, with 55% of bivalve families being exploited, concentrated mostly in two major clades but all major body plans. We find that exploited species tend to be larger in size, occur in shallower waters, and have larger geographic and thermal ranges-the last two traits are known to confer extinction-resistance in marine bivalves. However, exploited bivalve species in certain regions such as the tropical east Atlantic and the temperate northeast and southeast Pacific, are among those with high intrinsic vulnerability and are a large fraction of regional faunal diversity. Our results pinpoint regional faunas and specific taxa of likely concern for management and conservation.
Assuntos
Bivalves , Ecossistema , Animais , Humanos , Evolução Biológica , Biodiversidade , Extinção BiológicaRESUMO
Current augmentative and alternative communication (AAC) devices require individuals in medical settings to spell, locate symbols or phrases, or use non-verbal communication to express health and personal information to family and medical staff. The purpose of this initial investigation was to examine the type (personal, family, staff, procedural, or health status), form or representation and frequency of items that could be used to represent communication content for people in inpatient rehabilitation settings. Results revealed that potential communication items within the personal or procedural categories were consistently represented in participants' rooms. Information related to medical staff was the least consistently represented and appeared to change frequently. The use of items to support the communication of patients with unmet communication needs is discussed.
Assuntos
Auxiliares de Comunicação para Pessoas com Deficiência , Instalações de Saúde , Comunicação não Verbal , Adulto , Idoso , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Centros de ReabilitaçãoRESUMO
Background: Comparative morphology fundamentally relies on the orientation and alignment of specimens. In the era of geometric morphometrics, point-based homologies are commonly deployed to register specimens and their landmarks in a shared coordinate system. However, the number of point-based homologies commonly diminishes with increasing phylogenetic breadth. These situations invite alternative, often conflicting, approaches to alignment. The bivalve shell (Mollusca: Bivalvia) exemplifies a homologous structure with few universally homologous points-only one can be identified across the Class, the shell 'beak'. Here, we develop an axis-based framework, grounded in the homology of shell features, to orient shells for landmark-based, comparative morphology. Methods: Using 3D scans of species that span the disparity of shell morphology across the Class, multiple modes of scaling, translation, and rotation were applied to test for differences in shell shape. Point-based homologies were used to define body axes, which were then standardized to facilitate specimen alignment via rotation. Resulting alignments were compared using pairwise distances between specimen shapes as defined by surface semilandmarks. Results: Analysis of 45 possible alignment schemes finds general conformity among the shape differences of 'typical' equilateral shells, but the shape differences among atypical shells can change considerably, particularly those with distinctive modes of growth. Each alignment corresponds to a hypothesis about the ecological, developmental, or evolutionary basis of morphological differences, but we suggest orientation via the hinge line for many analyses of shell shape across the Class, a formalization of the most common approach to morphometrics of shell form. This axis-based approach to aligning specimens facilitates the comparison of approximately continuous differences in shape among phylogenetically broad and morphologically disparate samples, not only within bivalves but across many other clades.
Assuntos
Bivalves , Animais , Filogenia , Bivalves/anatomia & histologia , Evolução Biológica , MatemáticaRESUMO
BACKGROUND: Understanding the experience of training in an authentic and rich way can be a powerful driver to reviewing teaching and learning practice. GP educators in the Health Education England Wessex region decided to take this a step further and examine the equity of the experience of training, including trainees' thoughts and views about how that experience could be improved. METHOD: An online questionnaire survey was developed covering topics such as the perceived support needs of IMG (international medical graduate) trainees, trainees' experiences of discrimination, and their ideas for improvement. The survey focused on areas that were within the power of local educators to change, thereby enabling the results to drive improvement. The survey link was emailed to all trainees in our deanery via their training patches. Responses were anonymous. RESULTS: One hundred and eighty-seven responses were received from a cohort of approximately 530 trainees-a response rate of 35%. Responses ranged from a limited awareness of additional support needs for trainees from different backgrounds, through to those who had experienced uncomfortable situations and those with clear ideas about improvements. The data have been used to trigger improvement discussions within patch teams and facilitate changes in practice. CONCLUSIONS: The outcome of the work has led to change-from providing additional courses and support to raising awareness of trainees' experiences. The results have also been fed back to senior educators who manage training across the region.
Assuntos
Competência Clínica , Educação de Pós-Graduação em Medicina , Inglaterra , Humanos , Aprendizagem , Inquéritos e QuestionáriosRESUMO
The peptide hormone, angiotensin (Ang-(1-7)), produces anti-inflammatory and protective effects by inhibiting production and expression of many cytokines and adhesion molecules that are associated with a cytokine storm. While Ang-(1-7) has been shown to reduce inflammation and airway hyperreactivity in models of asthma, little is known about the effects of Ang-(1-7) during live respiratory infections. Our studies were developed to test if Ang-(1-7) is protective in the lung against overzealous immune responses during an infection with Mycoplasma pneumonia (Mp), a common respiratory pathogen known to provoke exacerbations in asthma and COPD patients. Wild type mice were treated with infectious Mp and a subset of was given either Ang-(1-7) or peptide-free vehicle via oropharyngeal delivery within 2 h of infection. Markers of inflammation in the lung were assessed within 24 h for each set of animals. During Mycoplasma infection, one high dose of Ang-(1-7) delivered to the lungs reduced neutrophilia and Muc5ac, as well as Tnf-α and chemokines (Cxcl1) associated with acute respiratory distress syndrome (ARDS). Despite decreased inflammation, Ang-(1-7)-treated mice also had significantly lower Mp burden in their lung tissue, indicating decreased airway colonization. Ang-(1-7) also had an impact on RAW 264.7 cells, a commonly used macrophage cell line, by dose-dependently inhibiting TNF-α production while promoting Mp killing. These new findings provide additional support to the protective role(s) of Ang1-7 in controlling inflammation, which we found to be highly protective against live Mp-induced lung inflammation.
RESUMO
Dynamins induce membrane vesiculation during endocytosis and Golgi budding in a process that requires assembly-dependent GTPase activation. Brain-specific dynamin 1 has a weaker propensity to self-assemble and self-activate than ubiquitously expressed dynamin 2. Here we show that dynamin 3, which has important functions in neuronal synapses, shares the self-assembly and GTPase activation characteristics of dynamin 2. Analysis of dynamin hybrids and of dynamin 1-dynamin 2 and dynamin 1-dynamin 3 heteropolymers reveals that concentration-dependent GTPase activation is suppressed by the C-terminal proline/arginine-rich domain of dynamin 1. Dynamin proline/arginine-rich domains also mediate interactions with SH3 domain-containing proteins and thus regulate both self-association and heteroassociation of dynamins.
Assuntos
Arginina/química , Dinaminas/química , Dinaminas/metabolismo , Prolina/química , Animais , Linhagem Celular , Dinamina I/química , Dinamina I/genética , Dinamina I/metabolismo , Dinamina II/química , Dinamina II/genética , Dinamina II/metabolismo , Dinamina III/química , Dinamina III/genética , Dinamina III/metabolismo , Dinaminas/genética , Humanos , Domínios Proteicos Ricos em Prolina/genética , Domínios Proteicos Ricos em Prolina/fisiologia , Estrutura Terciária de Proteína , SpodopteraRESUMO
Fragile X syndrome is caused by FMR1 gene silencing and loss of the encoded fragile X mental retardation protein (FMRP), which binds to mRNA and regulates translation. Studies in the Fmr1-/y mouse model of fragile X syndrome indicate that aberrant cerebral protein synthesis downstream of metabotropic glutamate receptor 5 (mGluR5) signaling contributes to disease pathogenesis, but clinical trials using mGluR5 inhibitors were not successful. Animal studies suggested that treatment with lithium might be an alternative approach. Targets of lithium include paralogs of glycogen synthase kinase 3 (GSK3), and nonselective small-molecule inhibitors of these enzymes improved disease phenotypes in a fragile X syndrome mouse model. However, the potential therapeutic use of GSK3 inhibitors has been hampered by toxicity arising from inhibition of both α and ß paralogs. Recently, we developed GSK3 inhibitors with sufficient paralog selectivity to avoid a known toxic consequence of dual inhibition, that is, increased ß-catenin stabilization. We show here that inhibition of GSK3α, but not GSK3ß, corrected aberrant protein synthesis, audiogenic seizures, and sensory cortex hyperexcitability in Fmr1-/y mice. Although inhibiting either paralog prevented induction of NMDA receptor-dependent long-term depression (LTD) in the hippocampus, only inhibition of GSK3α impaired mGluR5-dependent and protein synthesis-dependent LTD. Inhibition of GSK3α additionally corrected deficits in learning and memory in Fmr1-/y mice; unlike mGluR5 inhibitors, there was no evidence of tachyphylaxis or enhanced psychotomimetic-induced hyperlocomotion. GSK3α selective inhibitors may have potential as a therapeutic approach for treating fragile X syndrome.
Assuntos
Síndrome do Cromossomo X Frágil , Animais , Modelos Animais de Doenças , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Quinase 3 da Glicogênio Sintase , Hipocampo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Traumatic brain injury (TBI) is the commonest cause of disability in under-40-year-olds. Vestibular features of dizziness (illusory self-motion) or imbalance which affects 50% of TBI patients at 5 years, increases unemployment threefold in TBI survivors. Unfortunately, vestibular diagnoses are cryptogenic in 25% of chronic TBI cases, impeding therapy. We hypothesized that chronic adaptive brain mechanisms uncouple vestibular symptoms from signs. This predicts a masking of vestibular diagnoses chronically but not acutely. Hence, defining the spectrum of vestibular diagnoses in acute TBI should clarify vestibular diagnoses in chronic TBI. There are, however, no relevant acute TBI data. Of 111 Major Trauma Ward adult admissions screened (median 38-years-old), 96 patients (87%) had subjective dizziness (illusory self-motion) and/or objective imbalance were referred to the senior author (BMS). Symptoms included: feeling unbalanced (58%), headache (50%) and dizziness (40%). In the 47 cases assessed by BMS, gait ataxia was the commonest sign (62%) with half of these cases denying imbalance when asked. Diagnoses included BPPV (38%), acute peripheral unilateral vestibular loss (19%), and migraine phenotype headache (34%), another potential source of vestibular symptoms. In acute TBI, vestibular signs are common, with gait ataxia being the most frequent one. However, patients underreport symptoms. The uncoupling of symptoms from signs likely arises from TBI affecting perceptual mechanisms. Hence, the cryptogenic nature of vestibular symptoms in TBI (acute or chronic) relates to a complex interaction between injury (to peripheral and central vestibular structures and perceptual mechanisms) and brain-adaptation, emphasizing the need for acute prospective, mechanistic studies.
Assuntos
Lesões Encefálicas Traumáticas , Marcha Atáxica , Cefaleia , Doenças Vestibulares , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/diagnóstico , Lesões Encefálicas Traumáticas/fisiopatologia , Feminino , Marcha Atáxica/diagnóstico , Marcha Atáxica/etiologia , Marcha Atáxica/fisiopatologia , Cefaleia/diagnóstico , Cefaleia/etiologia , Cefaleia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Vestibulares/diagnóstico , Doenças Vestibulares/etiologia , Doenças Vestibulares/fisiopatologia , Adulto JovemRESUMO
Many aspects of climate affect the deployment of biodiversity in time and space, and so changes in climate might be expected to drive regional and global extinction of both taxa and their ecological functions. Here we examine the association of past climate changes with extinction in marine bivalves, which are increasingly used as a model system for macroecological and macroevolutionary analysis. Focusing on the Cenozoic Era (66 Myr ago to the present), we analyze extinction patterns in shallow-water marine bivalve genera relative to temperature dynamics as estimated from isotopic data in microfossils. When the entire Cenozoic timeseries is considered, extinction intensity is not significantly associated with the mean temperature or the detrended variance in temperature within a given time interval (stratigraphic stage). However, extinction increases significantly with both the rate of temperature change within the stage of extinction and the absolute change in mean temperature from the preceding stage to the stage of extinction. Thus, several extinction events, particularly the extinction pulse near the Pliocene-Pleistocene boundary, do appear to have climatic drivers. Further, the latitudinal diversity gradient today and the Cenozoic history of polar faunas suggest that long-term, regional extinctions associated with cooling removed not just taxa but a variety of ecological functions from high-latitude seas. These dynamics of biodiversity loss contrast with the two mass extinctions bracketing the Mesozoic Era, which had negligible effects on the diversity of ecological functions despite removing nearly as many taxa as the latitudinal gradient does today. Thus, the fossil record raises a key issue: whether the biotic consequences of present-day stresses will more closely resemble the long-term effects of past climate changes or those that cascaded from the mass extinctions.
Assuntos
Biodiversidade , Bivalves , Mudança Climática , Extinção Biológica , Animais , Bivalves/classificação , Fósseis , Oceanos e MaresRESUMO
The fossil record provides empirical patterns of morphological change through time and is central to the study of the tempo and mode of evolution. Here we apply likelihood-based time-series analyses to the near-continuous fossil record of Neogene planktonic foraminifera and reveal a morphological shift along the Truncorotalia lineage. Based on a geometric morphometric dataset of 1,459 specimens, spanning 5.9-4.5 Ma, we recover a shift in the mode of evolution from a disparate latest Miocene morphospace to a highly constrained early Pliocene morphospace. Our recovered dynamics are consistent with those stipulated by Simpson's quantum evolution and Eldredge-Gould's punctuated equilibria and supports previous suppositions that even within a single lineage, evolutionary dynamics require a multi-parameter model framework to describe. We show that foraminiferal lineages are not necessarily gradual and can experience significant and rapid transitions along their evolutionary trajectories and reaffirm the utility of multivariate datasets for their future research.
RESUMO
BACKGROUND: This study aims to determine the nature of United States Institutional Review Board (IRB) policy in a broad spectrum of research settings regarding the return of results to study participants. METHOD: IRB policies or standard operating procedures of 207 Medical School, Industry and Non-medical School IRBs were examined on-line to determine if they incorporated specific reference to the return of results to participants at the conclusion of the research. RESULTS: The majority of IRBs had no available policy regarding the return of research results to participants [56% (n = 116)]. A further third 136.3% (n = 75)] had policies that were defined as vague or that only indirectly mentioned the return of results. Medical School IRBs were more likely to have a policy than Industry or Non-medical University IRBs, respectively (odds ratio, 4.63; 95% confidence interval, 1.84 to 11.66 and odds ratio, 3.03; 95 % confidence interval, 1.75 to 5.25). Few provided any guidance as to the process of return of results. Of the IRBs that had a research results policy, 54.9% (n = 50) specifically addressed genetic research. CONCLUSIONS: Our findings demonstrate a marked lack of uniformity in IRB policy regarding the return of study results with over half providing no guidance.