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1.
Proc Biol Sci ; 288(1945): 20202927, 2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33622123

RESUMO

Extinction events in the geological past are similar to the present-day biodiversity crisis in that they have a pronounced biogeography, producing dramatic changes in the spatial distributions of species. Reconstructing palaeobiogeographic patterns from fossils therefore allows us to examine the long-term processes governing the formation of regional biotas, and potentially helps build spatially explicit models for future biodiversity loss. However, the extent to which biogeographic patterns can be preserved in the fossil record is not well understood. Here, we perform a suite of simulations based on the present-day distribution of North American mammals, aimed at quantifying the preservation potential of beta diversity and spatial richness patterns over extinction events of varying intensities, and after applying a stepped series of taphonomic filters. We show that taphonomic biases related to body size are the biggest barrier to reconstructing biogeographic patterns over extinction events, but that these may be compensated for by both the small mammal record preserved in bird castings, as well as range expansion in surviving species. Overall, our results suggest that the preservation potential of biogeographic patterns is surprisingly high, and thus that the fossil record represents an invaluable dataset recording the changing spatial distribution of biota over key intervals in Earth History.


Assuntos
Extinção Biológica , Fósseis , Animais , Biodiversidade , Tamanho Corporal , Mamíferos
2.
Am Nat ; 196(3): 271-290, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32813992

RESUMO

AbstractHuman-mediated species invasion and climate change are leading to global extinctions and are predicted to result in the loss of important axes of phylogenetic and functional diversity. However, the long-term robustness of modern communities to invasion is unknown, given the limited timescales over which they can be studied. Using the fossil record of the Paleocene-Eocene thermal maximum (PETM; ∼56 Ma) in North America, we evaluate mammalian community-level response to a rapid global warming event (5°-8°C) and invasion by three Eurasian mammalian orders and by species undergoing northward range shifts. We assembled a database of 144 species body sizes and created a time-scaled composite phylogeny. We calculated the phylogenetic and functional diversity of all communities before, during, and after the PETM. Despite increases in the phylogenetic diversity of the regional species pool, phylogenetic diversity of mammalian communities remained relatively unchanged, a pattern that is invariant to the tree dating method, uncertainty in tree topology, and resolution. Similarly, body size dispersion and the degree of spatial taxonomic turnover of communities remained similar across the PETM. We suggest that invasion by new taxa had little impact on Paleocene-Eocene mammal communities because niches were not saturated. Our findings are consistent with the numerous studies of modern communities that record little change in community-scale richness despite turnover in taxonomic composition during invasion. What remains unknown is whether long-term robustness to biotic and abiotic perturbation are retained by modern communities given global anthropogenic landscape modification.


Assuntos
Distribuição Animal , Biodiversidade , Tamanho Corporal , Mudança Climática , Mamíferos/anatomia & histologia , Mamíferos/fisiologia , Animais , Fósseis/anatomia & histologia , América do Norte , Filogenia
3.
Proc Biol Sci ; 284(1861)2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28835549

RESUMO

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones-all adaptations for suction feeding upon fishes and squid. We report a new fossil odontocete from the Oligocene (approx. 30 Ma) of South Carolina (Inermorostrum xenops, gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour among modern Odontoceti.


Assuntos
Evolução Biológica , Golfinhos/classificação , Comportamento Alimentar , Filogenia , Animais , Fósseis , Dente , Baleias
4.
Biol Lett ; 12(6)2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27330176

RESUMO

Understanding extinction drivers in a human-dominated world is necessary to preserve biodiversity. We provide an overview of Quaternary extinctions and compare mammalian extinction events on continents and islands after human arrival in system-specific prehistoric and historic contexts. We highlight the role of body size and life-history traits in these extinctions. We find a significant size-bias except for extinctions on small islands in historic times. Using phylogenetic regression and classification trees, we find that while life-history traits are poor predictors of historic extinctions, those associated with difficulty in responding quickly to perturbations, such as small litter size, are good predictors of prehistoric extinctions. Our results are consistent with the idea that prehistoric and historic extinctions form a single continuing event with the same likely primary driver, humans, but the diversity of impacts and affected faunas is much greater in historic extinctions.


Assuntos
Extinção Biológica , Mamíferos/fisiologia , Animais , Tamanho Corporal , Atividades Humanas , Humanos , Ilhas , Estágios do Ciclo de Vida , Mamíferos/anatomia & histologia , Mamíferos/classificação , Filogenia
5.
J Exp Biol ; 218(Pt 10): 1538-47, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25852070

RESUMO

Microwear, the quantification of microscopic scratches and pits on the occlusal surfaces of tooth enamel, is commonly used as a paleodietary proxy. For ungulates (hoofed mammals), scratch-dominant microwear distinguishes modern grazers from browsers, presumably as a result of abrasion from grass phytoliths (biogenic silica). However, it is also likely that exogenous grit (i.e. soil, dust) is a contributing factor to these scratch-dominant patterns, which may reflect soil ingestion that varies with feeding height and/or environmental conditions (e.g. dust production in open and/or arid habitats). This study assessed the contribution of exogenous grit to tooth wear by measuring the effects of fine- and medium-grained silica sand on tooth enamel using a novel live-animal tooth-molding technique. It therefore constitutes the first controlled feeding experiment using ungulates and the first in vivo experiment using abrasives of different sizes. Four sheep were fed three diet treatments: (1) a mixture of Garrison and Brome hay (control), (2) hay treated with fine-grained silica sand (180-250 µm) and (3) hay treated with medium-grained silica sand (250-425 µm). We found a significant increase in pit features that was correlated with an increase in grain size of grit, corroborating earlier chewing simulation experiments that produced pits through grit-induced abrasion (i.e. the 'grit effect'). Our results support an interpretation of large silica grains fracturing to create smaller, more abundant angular particles capable of abrasion, with jaw movement defining feature shape (i.e. scratch or pit).


Assuntos
Esmalte Dentário/patologia , Alimentos , Ovinos , Abrasão Dentária/veterinária , Ração Animal , Animais , Dieta/veterinária , Feminino , Dente Molar/patologia , Tamanho da Partícula , Poaceae , Dióxido de Silício , Abrasão Dentária/etiologia , Abrasão Dentária/patologia
6.
Ecol Evol ; 14(3): e11006, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38500863

RESUMO

Annual antler growth begins in the spring and is completed by late summer for male caribou (Rangifer tarandus groenlandicus) from the Qamanirjuaq herd (Nunavut, Canada), aligned with both the spring migration and a seasonal dietary shift. Antlers may provide a non-lethal means of studying short- and long-term changes in caribou ecology through incorporated isotopes of carbon (δ13C) and nitrogen (δ15N). We sampled the antlers of 12 male caribou from the Qamanirjuaq herd culled in September 1967. We predicted that serial sampling of antlers would reflect the known seasonal dietary change from lichen to grass-like and shrub diet based on rumen contents from individuals culled during the same period. The δ13C and δ15N were analyzed in food sources and every 3 cm along each antler's length. The carbon isotope compositions of collagen (δ13Ccol) varied by ~0.5‰ among individuals and within antlers, while the carbon isotope compositions of antler bioapatite (δ13CCO3) increased by 1-1.5‰ from pedicle to tip. Values of δ15Ncol increased within antlers by 1-3‰ from pedicle to tip and varied by 3‰ among the individuals sampled. Antler collagen was lower in δ15Ncol by ~1‰ relative to bone collagen. Bayesian mixing models were conducted to test for changes in dietary proportions from antler isotope compositions. Mixing models did not indicate significant dietary shifts for any individual during antler formation, showing consistently mixed diets of fungi, horsetail, lichen, and woody plants. Increases in δ15Ncol in antler tissue could, therefore, correspond to subtle seasonal dietary changes and/or the physiological stress of antler tissue development.

7.
J Mamm Evol ; 29(4): 863-875, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36438779

RESUMO

The metapodials of extinct horses have long been regarded as one of the most useful skeletal elements to determine taxonomic identity. However, recent research on both extant and extinct horses has revealed the possibility for plasticity in metapodial morphology, leading to notable variability within taxa. This calls into question the reliability of metapodials in species identification, particularly for species identified from fragmentary remains. Here, we use ten measurements of metapodials from 203 specimens of four Pleistocene horse species from eastern Beringia to test whether there are significant differences in metapodial morphology that support the presence of multiple species. We then reconstruct the body masses for every specimen to assess the range in body size within each species and determine whether species differ significantly from one another in mean body mass. We find that that taxonomic groups are based largely on the overall size of the metapodial, and that all metapodial measurements are highly autocorrelated. We also find that mean body mass differs significantly among most, but not all, species. We suggest that metapodial measurements are unreliable taxonomic indicators for Beringian horses given evidence for plasticity in metapodial morphology and their clear reflection of differences in body mass. We recommend future studies use more reliable indicators of taxonomy to identify Beringian horse species, particularly from localities from which fossils of several species have been recovered. Supplementary Information: The online version contains supplementary material available at 10.1007/s10914-022-09626-4.

8.
J Mammal ; 103(1): 2-17, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35087328

RESUMO

Modern North American carnivorous mammal assemblages consist of species from a single clade: the Carnivora. Carnivorans once coexisted with members of other meat-eating clades, including the creodonts (Hyaenodontida and Oxyaenida). Creodonts, however, went extinct in North America during the late Eocene and early Oligocene, potentially due to niche overlap and resource competition with contemporary carnivorans. In this study, we employ a community ecology approach to understand whether the dietary niches of coexisting creodonts and carnivorans overlapped during the late Eocene (Chadronian North American Land Mammal Age), a time when creodonts were dwindling and carnivorans were diversifying. We quantify niche overlap based on inferences of diet from carnassial tooth shape estimated using Orientation Patch Count, Dirichlet's Normal Surface Energy, and linear dental measurements as well as from body mass for all species in the Calf Creek Local Fauna of Cypress Hills, Saskatchewan (Treaty 4 land). Although creodonts and carnivorans shared characteristics of their carnassial tooth shape, suggesting similar chewing mechanics and feeding habits, we find that marked differences in body size likely facilitated niche partitioning, at least between the largest creodonts and carnivorans. Calculations of prey focus masses and prey mass spectra indicate that only the smallest creodont may have experienced significant competition for prey with the coeval carnivorans. We suggest that the ultimate extinction of creodonts from North America during the late Eocene and Oligocene was unlikely to have been driven by factors related to niche overlap with carnivorans.

9.
Nat Commun ; 13(1): 3940, 2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803946

RESUMO

Biotic homogenization-increasing similarity of species composition among ecological communities-has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (~30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (~20,000-14,000 ybp). From ~10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at ~10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (~2,000-1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back ~10,000 years.


Assuntos
Biodiversidade , Extinção Biológica , Fósseis , Mamíferos , Agricultura , Animais , Tamanho Corporal , Ecossistema , Humanos , América do Norte , Crescimento Demográfico
10.
Ecol Evol ; 11(23): 17005-17021, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34938488

RESUMO

Stable oxygen isotope (δ18O) compositions from vertebrate tooth enamel are widely used as biogeochemical proxies for paleoclimate. However, the utility of enamel oxygen isotope values for environmental reconstruction varies among species. Herein, we evaluate the use of stable oxygen isotope compositions from pronghorn (Antilocapra americana Gray, 1866) enamel for reconstructing paleoclimate seasonality, an elusive but important parameter for understanding past ecosystems. We serially sampled the lower third molars of recent adult pronghorn from Wyoming for δ18O in phosphate (δ18OPO4) and compared patterns to interpolated and measured yearly variation in environmental waters as well as from sagebrush leaves, lakes, and rivers (δ18Ow). As expected, the oxygen isotope compositions of phosphate from pronghorn enamel are enriched in 18O relative to environmental waters. For a more direct comparison, we converted δ18Ow values into expected δ18OPO4* values (δ18OW-PO4*). Pronghorn δ18OPO4 values from tooth enamel record nearly the full amplitude of seasonal variation from Wyoming δ18OW-PO4* values. Furthermore, pronghorn enamel δ18OPO4 values are more similar to modeled δ18OW-PO4* values from plant leaf waters than meteoric waters, suggesting that they obtain much of their water from evaporated plant waters. Collectively, our findings establish that seasonality in source water is reliably reflected in pronghorn enamel, providing the basis for exploring changes in the amplitude of seasonality of ancient climates. As a preliminary test, we sampled historical pronghorn specimens (1720 ± 100 AD), which show a mean decrease (a shift to lower values) of 1-2‰ in δ18OPO4 compared to the modern specimens. They also exhibit an increase in the δ18O amplitude, representing an increase in seasonality. We suggest that the cooler mean annual and summer temperatures typical of the 18th century, as well as enhanced periods of drought, drove differences among the modern and historical pronghorn, further establishing pronghorn enamel as excellent sources of paleoclimate proxy data.

11.
Health Phys ; 121(5): 531-534, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34411056

RESUMO

ABSTRACT: Brachytherapy programs within radiation therapy departments are subject to stringent radiation safety requirements in order to ensure the safety of the staff and patients. Training programs often include brachytherapy-specific radiation safety training modules that address the specific risks associated with radioactive sources, emergency procedures, and regulatory requirements specific to the use of radioisotopes. Unlike other uses of radioactive materials, brachytherapy uses sealed sources and therefore under routine operations does not encounter radioactive contaminants. This article presents an unusual clinical situation in which an 125I brachytherapy seed was damaged during routine clinical workflow, resulting in radioactive contamination within the clinical environment. Decisions made at the time of the incident resulted in contamination that spread beyond the initial location. The incident highlighted a shortcoming of the radiation safety program in preparing staff for the possibility of having to deal with unsealed radioactivity. Brachytherapy programs would be strengthened by including training specific to radioactive contamination in their emergency training to equip staff to respond to unexpected damage to the sealed sources.


Assuntos
Braquiterapia , Lesões por Radiação , Proteção Radiológica , Braquiterapia/efeitos adversos , Braquiterapia/métodos , Humanos , Radioisótopos do Iodo/efeitos adversos , Lesões por Radiação/tratamento farmacológico , Proteção Radiológica/métodos
12.
Trends Ecol Evol ; 36(1): 61-75, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33067015

RESUMO

Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions using data on fossil and modern biodiversity. Important developments in three primary areas of research include analysis of (i) macroevolutionary rates, (ii) the impacts of and recovery from extinction events, and (iii) how humans (Homo sapiens) affected interactions among non-human species. We present multiple lines of evidence for an important and measurable role of biotic interactions in shaping the evolution of communities and lineages on long timescales.


Assuntos
Biodiversidade , Fósseis , Evolução Biológica , Mudança Climática
13.
Med Phys ; 37(6): 2787-95, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20632589

RESUMO

PURPOSE: It is common practice to correct for interfraction motion by shifting the patient from reference skin marks to better align the internal target at the linear accelerator's isocenter. Shifting the patient away from skin mark alignment causes the radiation beams to pass through a patient geometry different from that planned. Yet, dose calculations on the new geometry are not commonly performed. The intention of this work was to compare the dosimetric consequences of treating the patient with and without setup correction for the common clinical scenario of prostate interfraction motion. METHODS: In order to account for prostate motion, 32 patients initially aligned to the room lasers via skin marks were realigned under the treatment beams by shifting the treatment couch based on ultrasound image guidance. An intramodality 3D ultrasound image guidance system was used to determine the setup correction, so that errors stemming from different tissue representations on different imaging modalities were eliminated. Two scenarios were compared to the reference static treatment plan: (1) Uncorrected patient alignment and (2) corrected patient alignment. Prostate displacement statistics and the dose to the clinical target volume (CTV), bladder, and rectum are reported. Monte Carlo dose calculation methods were employed. RESULTS: Comparing the uncorrected and corrected scenarios using the static treatment plan as the reference, the average percent difference in D95 for the CTV improved from -5.1% (range -40%, 1.3%) to 0.0% (-3.5%, 2.0%) and the average percent difference in V90 for the bladder and rectum changed from -11% (-84%, 232%) to -8.3% (-61%, 5.2%) and from -47% (-100%, 108%) to 0.9% (-62%, 102%), respectively. There was no simple correlation between displacement and dose discrepancy before correction. After patient realignment, the prescribed dose to the CTV was achieved within 1% for 75% (24/32) of the patients. After patient realignment, 50% of the patients had doses that differed from the static treatment plan by 25% for the bladder and 8% for the rectum. CONCLUSIONS: The dose degradation due to prostate motion (before correction) is not accurately predicted from the average trends for all patients. Outliers included smaller displacements that lead to larger dosimetric differences in the corrected scenario, especially for the bladder and rectum, which exhibited doses substantially different from that planned.


Assuntos
Aumento da Imagem/métodos , Imageamento Tridimensional/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radiometria/métodos , Radioterapia Assistida por Computador/métodos , Ultrassonografia/métodos , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
J Appl Clin Med Phys ; 10(4): 241-251, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-19918222

RESUMO

Proven conventional dosimetry techniques do not provide accuracy and precision in the measurement of inverse planned intensity modulated radiation therapy (IMRT) fields. Dynamic and step-and-shoot multileaf collimation (DMLC/SMLC) challenge current ionization chamber dosimetry practices. Ionization chamber performance in these fields is evaluated for three cylindrical chambers of varying volumes (PinPoint (PP): 0.015 cm3, IC10: 0.13 cm3, Farmer type NE2571 (FT): 0.69 cm3) in terms of measurement reproducibility, dose measurement linearity, and IMRT dose measurements. Fifty IMRT patient specific quality assurance dose measurements were performed with each chamber. DMLC measurements are compared between chambers, and to dose calculations from a commercial treatment planning system (TPS) that used a finite size pencil beam model (FSPB). Ten SMLC measurements are compared to Monte Carlo simulations available in the TPS. The three chambers demonstrated adequate measurement reproducibility characteristics for both open and DMLC fields with each chamber able to perform within 2% (2SD) for DMLC fields. Both smaller volume chambers over responded (> 5%) when irradiated with a small number of monitor units in open fields. FT and IC10 chambers demonstrated dose linearity in DMLC fields down to 10 monitor units, while dose linearity for the PP chamber broke down at 100 monitor units. The evaluation of fifty DMLC treatment plan quality assurance procedures revealed that the FT chamber measurements were closest to the FSPB calculated values (FSPB: 1.0, FT: 0.973 +/- 0.044, IC10: 0.963 +/- 0.048, PP: 0.944 +/- 0.071). Quality assurance plans calculated independently with Monte Carlo more closely matched chamber measurements (FSPB: 1.0, MC: 0.97, FT: 0.95). Measurements of absorbed dose to water in IMRT fields are highly chamber and IMRT plan dependent.


Assuntos
Radiometria/instrumentação , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Humanos , Controle de Qualidade , Radiometria/classificação , Radiometria/métodos
15.
Science ; 365(6459): 1305-1308, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31604240

RESUMO

Large mammals are at high risk of extinction globally. To understand the consequences of their demise for community assembly, we tracked community structure through the end-Pleistocene megafaunal extinction in North America. We decomposed the effects of biotic and abiotic factors by analyzing co-occurrence within the mutual ranges of species pairs. Although shifting climate drove an increase in niche overlap, co-occurrence decreased, signaling shifts in biotic interactions. Furthermore, the effect of abiotic factors on co-occurrence remained constant over time while the effect of biotic factors decreased. Biotic factors apparently played a key role in continental-scale community assembly before the extinctions. Specifically, large mammals likely promoted co-occurrence in the Pleistocene, and their loss contributed to the modern assembly pattern in which co-occurrence frequently falls below random expectations.


Assuntos
Ecossistema , Extinção Biológica , Fósseis , Mamíferos , Animais , Mudança Climática , América do Norte , Paleontologia , Dinâmica Populacional
16.
Worldviews Evid Based Nurs ; 5(2): 75-84, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18559020

RESUMO

PURPOSE: To conduct a baseline assessment of nurses' perceptions of knowledge, attitude, and skill level related to evidence-based practice (EBP) and research utilisation; determine the level of organisational readiness for implementing EBP and research; and examine the effectiveness of a computer-based educational program on nurses' perceptions of knowledge, attitude, and skill level related to EBP and research utilisation. DESIGN: A descriptive, quasi-experimental design with a one-group, pre-intervention survey, intervention, and post-intervention survey method was used. A convenience sample of 744 nurses working in an integrated health care system was recruited. The study was conducted from May 2006 through November 2006. METHODS: Data collection instruments were a demographic data questionnaire and the Evidence-Based Nursing Questionnaire. An education intervention on principles of EBP and research utilisation was conducted via three computer-based learning modules. FINDINGS: Statistically significant differences in perceptions of knowledge, attitude, and skill level, as well as beliefs about organisational readiness were found after nurses participated in the computer-based education intervention. Although nurses indicated having positive attitudes about using research to support best nursing practice, gaps in knowledge and skills in retrieving research publications, evaluating the evidence, and incorporating the evidence into practice remain. Nurses rated their managers, senior nursing administrators, and staff nurses on their unit higher than hospital managers in supporting changes to practice based on research. CONCLUSIONS: Nurses in clinical settings need to be able to use research findings and incorporate EBP into their nursing practice to promote positive patient outcomes. Appropriate organisational infrastructures are essential for promoting EBP and research utilisation in clinical settings. Diverse and effective methods are essential in educating and engaging nurses in EBP and research utilisation. Computer-based education is an effective approach that can be used by nursing leaders in health care organisations to educate and engage nurses in EBP initiatives and research utilisation.


Assuntos
Instrução por Computador , Educação Continuada em Enfermagem/métodos , Medicina Baseada em Evidências , Conhecimentos, Atitudes e Prática em Saúde , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados de Enfermagem/psicologia , Cuidados de Enfermagem/tendências , Pesquisa em Enfermagem/educação , Inquéritos e Questionários , Estados Unidos
17.
Ecol Evol ; 8(22): 11363-11367, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30519449

RESUMO

In response to DeSantis et al., we describe that the presence of phylogenetic signal in tooth wear dietary niche proxies is likely a result of the evolutionary process. We also address their concerns regarding enforcement of the use of phylogenetic comparative methods by editors of ecology and evolution journals.

18.
Ecol Evol ; 8(11): 5355-5368, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29938058

RESUMO

In the absence of independent observational data, ecologists and paleoecologists use proxies for the Eltonian niches of species (i.e., the resource or dietary axes of the niche). Some dietary proxies exploit the fact that mammalian teeth experience wear during mastication, due to both tooth-on-tooth and food-on-tooth interactions. The distribution and types of wear detectible at micro- and macroscales are highly correlated with the resource preferences of individuals and, in turn, species. Because methods that quantify the distribution of tooth wear (i.e., analytical tooth wear methods) do so by direct observation of facets and marks on the teeth of individual animals, dietary inferences derived from them are thought to be independent of the clade to which individuals belong. However, an assumption of clade or phylogenetic independence when making species-level dietary inferences may be misleading if phylogenetic niche conservatism is widespread among mammals. Herein, we test for phylogenetic signal in data from numerous analytical tooth wear studies, incorporating macrowear (i.e., mesowear) and microwear (i.e., low-magnification microwear and dental microwear texture analysis). Using two measures of phylogenetic signal, heritability (H2) and Pagel's λ, we find that analytical tooth wear data are not independent of phylogeny and failing to account for such nonindependence leads to overestimation of discriminability among species with different dietary preferences. We suggest that morphological traits inherited from ancestral clades (e.g., tooth shape) influence the ways in which the teeth wear during mastication and constrain the foods individuals of a species can effectively exploit. We do not suggest that tooth wear is simply phylogeny in disguise; the tooth wear of individuals and species likely varies within some range that is set by morphological constraints. We therefore recommend the use of phylogenetic comparative methods in studies of mammalian tooth wear, whenever possible.

19.
Am J Crit Care ; 15(1): 86-94; quiz 95, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16391318

RESUMO

BACKGROUND: Neuromuscular blocking agents used for therapeutic purposes, such as facilitating mechanical ventilation and relieving life-threatening agitation, paralyze patients but leave them fully conscious. Aggressive sedation or analgesia is necessary to reduce awareness, relieve fear, produce comfort, decrease anxiety, induce unconsciousness, and minimize possible complications such as posttraumatic stress syndrome. Little information is available on the extent to which patients experience awareness during therapeutic paralysis. OBJECTIVES: To determine and describe the remembered experiences of critical care patients who were given neuromuscular blocking agents and sedatives and/or analgesics to facilitate mechanical ventilation, improve hemodynamic stability, and improve oxygenation. METHODS: A phenomenological approach with in-depth interviews with 11 patients was used. Data were analyzed by using the constant comparative approach. RESULTS: A total of 4 themes and 3 subthemes were identified. The first theme was back and forth between reality and the unreal, between life and death; the subtheme was having weird dreams. The second theme was loss of control; the 2 subthemes were (1) fighting or being tied down and (2) being scared. The third theme was almost dying, and the fourth theme was feeling cared for. CONCLUSIONS: Patients can remember having both negative and positive experiences during neuromuscular blockade. Steps to improve the experiences of patients receiving neuromuscular blockers include improving assessment parameters, developing and using sedation/analgesia guidelines, and investing in quality improvement programs to provide assessment of awareness during therapeutic paralysis and follow-up and referral as necessary. Ways to decrease the use of neuromuscular blockers would also be useful.


Assuntos
Cuidados Críticos/métodos , Imobilização/psicologia , Pacientes Internados/psicologia , Unidades de Terapia Intensiva , Memória/fisiologia , Bloqueadores Neuromusculares/uso terapêutico , Adulto , Idoso , Analgesia/psicologia , Ansiedade/psicologia , Conscientização/efeitos dos fármacos , Sedação Consciente/psicologia , Sonhos/psicologia , Feminino , Humanos , Imobilização/métodos , Entrevistas como Assunto/métodos , Masculino , Pessoa de Meia-Idade , Dor/prevenção & controle , Dor/psicologia
20.
Am J Nurs ; 115(12): 49-58, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26600359

RESUMO

OBJECTIVE: Research is needed to determine the feasibility of implementing a dedicated ICU mobility team in community hospital settings. The purpose of this study was to assess, in one such hospital, four nurse-sensitive quality-of-care outcomes (falls, ventilator-associated events, pressure ulcers, and catheter-associated urinary tract infections [CAUTIs]), as well as hospital costs, sedation and delirium measures, and functional outcomes by comparing ICU patients who received physical therapy from a dedicated mobility team with ICU patients who received routine care. METHODS: We conducted a retrospective longitudinal study at a community acute care hospital; patients were randomly assigned to intervention or routine care groups. The mobility team screened patients Monday through Friday using a mobility algorithm to determine eligibility for participation in each early mobility session. Based on their strength, balance, hemodynamic stability, and ability to participate in early mobility activities, patients advanced through four progressively difficult phases of mobility. Data were collected and analyzed after patients were discharged from the hospital. RESULTS: The 66 patients who received the mobility intervention had significantly fewer falls, ventilator-associated events, pressure ulcers, and CAUTIs than the 66 patients in the routine care group. The mobility group also had lower hospital costs, fewer delirium days, lower sedation levels, and improved functional independence compared with the routine care group. Patients in the mobility group got out of bed on 2.5 more days than patients in the routine care group. There were also no adverse events in the mobility group. CONCLUSIONS: It is feasible for a community hospital to create and implement a dedicated ICU mobility team. Early mobilization of ICU patients contributed to fewer delirium days and improved patient outcomes, sedation levels, and functional status.


Assuntos
Pesquisa em Enfermagem Clínica/estatística & dados numéricos , Deambulação Precoce/estatística & dados numéricos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Indicadores de Qualidade em Assistência à Saúde , Acidentes por Quedas/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Pesquisa em Enfermagem Clínica/economia , Pesquisa em Enfermagem Clínica/métodos , Redução de Custos/métodos , Delírio/prevenção & controle , Deambulação Precoce/economia , Deambulação Precoce/métodos , Feminino , Hospitais Comunitários , Humanos , Unidades de Terapia Intensiva/economia , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos de Casos Organizacionais , Avaliação de Resultados em Cuidados de Saúde/economia , Equipe de Assistência ao Paciente/economia , Equipe de Assistência ao Paciente/organização & administração , Equipe de Assistência ao Paciente/estatística & dados numéricos , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Sudoeste dos Estados Unidos , Fatores de Tempo , Adulto Jovem
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