530 research outputs found

    Unveiling the underlying drivers of Phanerozoic marine diversification

    Get PDF
    In investigating global patterns of biodiversity through deep time, many large-scale drivers of diversification have been proposed, both biotic and abiotic. However, few robust conclusions about these hypothesized effectors or their roles have been drawn. Here, we use a linear stochastic differential equation (SDE) framework to test for the presence of underlying drivers of diversification patterns before examining specific hypothesized drivers. Using a global dataset of observations of skeletonized marine fossils, we infer origination, extinction and sampling rates (collectively called fossil time series) throughout the Phanerozoic using a capture–mark–recapture approach. Using linear SDEs, we then compare models including and excluding hidden (i.e. unmeasured) drivers of these fossil time series. We find evidence of large-scale underlying drivers of marine Phanerozoic diversification rates and present quantitative characterizations of these. We then test whether changing global temperature, sea-level, marine sediment area or continental fragmentation could act as drivers of the fossil time series. We show that it is unlikely any of these four abiotic factors are the hidden drivers we identified, though there is evidence for correlative links between sediment area and origination/extinction rates. Our characterization of the hidden drivers of Phanerozoic diversification and sampling will aid in the search for their ultimate identities

    Diverse Challenges Faced in Developing Sustainable Catchments

    Full text link

    NetProphet 2.0: Mapping transcription factor networks by exploiting scalable data resources

    Get PDF
    MOTIVATION: Cells process information, in part, through transcription factor (TF) networks, which control the rates at which individual genes produce their products. A TF network map is a graph that indicates which TFs bind and directly regulate each gene. Previous work has described network mapping algorithms that rely exclusively on gene expression data and \u27integrative\u27 algorithms that exploit a wide range of data sources including chromatin immunoprecipitation sequencing (ChIP-seq) of many TFs, genome-wide chromatin marks, and binding specificities for many TFs determined in vitro. However, such resources are available only for a few major model systems and cannot be easily replicated for new organisms or cell types. RESULTS: We present NetProphet 2.0, a \u27data light\u27 algorithm for TF network mapping, and show that it is more accurate at identifying direct targets of TFs than other, similarly data light algorithms. In particular, it improves on the accuracy of NetProphet 1.0, which used only gene expression data, by exploiting three principles. First, combining multiple approaches to network mapping from expression data can improve accuracy relative to the constituent approaches. Second, TFs with similar DNA binding domains bind similar sets of target genes. Third, even a noisy, preliminary network map can be used to infer DNA binding specificities from promoter sequences and these inferred specificities can be used to further improve the accuracy of the network map. AVAILABILITY AND IMPLEMENTATION: Source code and comprehensive documentation are freely available at https://github.com/yiming-kang/NetProphet_2.0. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online

    Pre-emptive morphine during therapeutic hypothermia after neonatal encephalopathy: a secondary analysis

    Get PDF
    Although therapeutic hypothermia (TH) improves outcomes after neonatal encephalopathy (NE), the safety and efficacy of preemptive opioid sedation during cooling therapy is unclear. We performed a secondary analysis of the data from a large multicountry prospective observational study (Magnetic Resonance Biomarkers in Neonatal Encephalopathy [MARBLE]) to examine the association of preemptive morphine infusion during TH on brain injury and neurodevelopmental outcomes after NE. All recruited infants had 3.0 Tesla magnetic resonance imaging and spectroscopy at 1 week, and neurodevelopmental outcome assessments at 22 months. Of 223 babies recruited to the MARBLE study, the data on sedation were available from 169 babies with moderate (n = 150) or severe NE (n = 19). Although the baseline characteristics and admission status were similar, the babies who received morphine infusion (n = 141) were more hypotensive (49% vs. 25%, p = 0.02) and had a significantly longer hospital stay (12 days vs. 9 days, p = 0.009) than those who did not (n = 28). Basal ganglia/thalamic injury (score ≥1) and cortical injury (score ≥1) was seen in 34/141 (24%) and 37/141 (26%), respectively, of the morphine group and 4/28 (14%) and 3/28 (11%) of the nonmorphine group (p > 0.05). On regression modeling adjusted for potential confounders, preemptive morphine was not associated with mean (standard deviation [SD]) thalamic N-acetylaspartate (NAA) concentration (6.9 ± 0.9 vs. 6.5 ± 1.5; p = 0.97), and median (interquartile range) lactate/NAA peak area ratios (0.16 [0.12–0.21] vs. 0.13 [0.11–0.18]; p = 0.20) at 1 week, and mean (SD) Bayley-III composite motor (92 ± 23 vs. 94 ± 10; p = 0.98), language (89 ± 22 vs. 93 ± 8; p = 0.53), and cognitive scores (95 ± 21 vs. 99 ± 13; p = 0.56) at 22 months. Adverse neurodevelopmental outcome (adjusted for severity of encephalopathy) was seen in 26 (18%) of the morphine group, and none of the nonmorphine group (p = 0.11). Preemptive morphine sedation during TH does not offer any neuroprotective benefits and may be associated with increased hospital stay. Optimal sedation during induced hypothermia requires further evaluation in clinical trials

    Retrieval evidence of impingement at the third articulation in contemporary dual mobility cups for total hip arthroplasty

    Get PDF
    PURPOSE: We aimed to assess polyethylene liners of retrieved hips of one design of a dual mobility (DM) cup liner and two designs of femoral stems to better understand the role of femoral stem design on polyethylene impingement. METHODS: This was a case-control study involving 70 retrieved highly cross-linked polyethylene (X3) liners used with ABGII (n = 35) and Rejuvenate (n = 35) stems (Stryker). All polyethylene liners were assessed for evidence of rim deformation and the damage quantified using metrology methods. RESULTS: A total of 80% of polyethylene liners paired with ABGII necks had macroscopic evidence of neck impingement resulting in a raised lip whilst 23% of liners paired with Rejuvenate necks had evidence of a raised lip (p < 0.0001). The height of the raised rims of the DM cups paired with ABGII necks had a median (range) of 139 μm (72-255). The height of the raised rims of the DM cups paired with Rejuvenate necks had a median (range) of 52 μm (45-90) (p < 0.0001). CONCLUSION: Our new findings from retrieved dual mobility bearings showed that polyethylene liner rim deformation resulting from impingement with the femoral neck occurs in early in-human function, is circumferential in distribution, and is affected by the stem neck design. We recommend the use of highly polished and non-edged neck designs when used in conjunction with DM cups

    Therapeutic hypothermia initiated within 6 hours of birth is associated with reduced brain injury on MR biomarkers in mild hypoxic ischemic encephalopathy: a non-randomised cohort study

    Get PDF
    Objective To examine the effect of therapeutic hypothermia on MR biomarkers and neurodevelopmental outcomes in babies with mild hypoxic-ischaemic encephalopathy (HIE). Design Non-randomised cohort study. Setting Eight tertiary neonatal units in the UK and the USA. Patients 47 babies with mild HIE on NICHD neurological examination performed within 6 hours after birth. Interventions Whole-body cooling for 72 hours (n=32) or usual care (n=15; of these 5 were cooled for <12 hours). Main outcome measures MRI and MR spectroscopy (MRS) within 2 weeks after birth, and a neurodevelopmental outcome assessment at 2 years. Results The baseline characteristics in both groups were similar except for lower 10 min Apgar scores (p=0.02) in the cooled babies. Despite this, the mean (SD) thalamic NAA/Cr (1.4 (0.1) vs 1.6 (0.2); p<0.001) and NAA/Cho (0.67 (0.08) vs 0.89 (0.11); p<0.001) ratios from MRS were significantly higher in the cooled group. Cooled babies had lower white matter injury scores than non-cooled babies (p=0.02). Four (27%) non-cooled babies with mild HIE developed seizures after 6 hours of age, while none of the cooled babies developed seizures (p=0.008). Neurodevelopmental outcomes at 2 years were available in 40 (85%) of the babies. Adverse outcomes were seen in 2 (14.3%) non-cooled babies, and none of the cooled babies (p=0.09). Conclusions Therapeutic hypothermia may have a neuroprotective effect in babies with mild HIE, as demonstrated by improved MRS biomarkers and reduced white matter injury on MRI. This may warrant further evaluation in adequately powered randomised controlled trials

    Integration of bow-tie plasmonic nano-antennas on tapered fibers

    Get PDF
    FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPIn this article, a new and flexible approach to control the electric field enhancement of bow-tie nano-antennas by integrating them on the lateral of a tapered optical fiber is proposed. The device is driven by a Q-switched laser and the performance of a fabricated nano-antenna in a quartz slide is tested by a Surface Enhanced Raman Scattering (SERS) experiment. A refractive index sensing experiment is also performed and a sensitivity of (240 +/- 30) nm/RIU is found in the 1.33-1.35 index range.25889868996FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2014/50632-6The Asian Office of Aerospace Research and Development (AOARD US Air Force FA2386-15-1-4084); Australian Research Council (ARC LP160100253); and Sao Paulo Research Foundation (FAPESP) (#2014/50632-6)

    UK Housing Market: Time Series Processes with Independent and Identically Distributed Residuals

    Get PDF
    The paper examines whether a univariate data generating process can be identified which explains the data by having residuals that are independent and identically distributed, as verified by the BDS test. The stationary first differenced natural log quarterly house price index is regressed, initially with a constant variance and then with a conditional variance. The only regression function that produces independent and identically distributed standardised residuals is a mean process based on a pure random walk format with Exponential GARCH in mean for the conditional variance. There is an indication of an asymmetric volatility feedback effect but higher frequency data is required to confirm this. There could be scope for forecasting the index but this is tempered by the reduction in the power of the BDS test if there is a non-linear conditional variance process

    How large should whales be?

    Full text link
    The evolution and distribution of species body sizes for terrestrial mammals is well-explained by a macroevolutionary tradeoff between short-term selective advantages and long-term extinction risks from increased species body size, unfolding above the 2g minimum size induced by thermoregulation in air. Here, we consider whether this same tradeoff, formalized as a constrained convection-reaction-diffusion system, can also explain the sizes of fully aquatic mammals, which have not previously been considered. By replacing the terrestrial minimum with a pelagic one, at roughly 7000g, the terrestrial mammal tradeoff model accurately predicts, with no tunable parameters, the observed body masses of all extant cetacean species, including the 175,000,000g Blue Whale. This strong agreement between theory and data suggests that a universal macroevolutionary tradeoff governs body size evolution for all mammals, regardless of their habitat. The dramatic sizes of cetaceans can thus be attributed mainly to the increased convective heat loss is water, which shifts the species size distribution upward and pushes its right tail into ranges inaccessible to terrestrial mammals. Under this macroevolutionary tradeoff, the largest expected species occurs where the rate at which smaller-bodied species move up into large-bodied niches approximately equals the rate at which extinction removes them.Comment: 7 pages, 3 figures, 2 data table

    Bryozoan genera Fenestrulina and Microporella no longer confamilial; multi-gene phylogeny supports separation

    Get PDF
    Bryozoans are a moderately diverse, mostly marine phylum with a fossil record extending to the early Ordovician. Compared to other phyla, little is known about their phylogenetic relationships at both lower and higher taxonomic levels. Hence, an effort is being made to elucidate the phylogenetic relationships among bryozoans. Here, we present newly sequenced nuclear and mitochondrial genes for 21 cheilostome bryozoans and compile these with existing orthologous molecular data. Using these data, we focus on reconstructing the phylogenetic relationships of Fenestrulina and Microporella, two species-rich genera. They are currently placed in a globally distributed family, Microporellidae, defined by having a semicircular primary orifice and a proximal ascopore, although there are indirect inferences in the morphological literature that suggest they might not be confamilial. Our six-gene phylogenetic analysis reveals that the genera Fenestrulina and Microporella are each monophyletic, with the sister clade to Microporella comprising non-microporellids. These genera thus have a polyphyletic relationship and should not be placed in the same family. Our result supports the reinstatement of the family Fenestrulinidae Jullien, 1888 for Fenestrulina and genera with comparable frontal shield and ooecial morphologies. Our well-supported phylogeny based on independent molecular data lends credit to existing phylogenetic hypotheses based on morphological observations but does not conform to the current classification of these particular bryozoans. This illustrates the general need for a rethink of bryozoan higher-level systematics, ideally based on both morphological and molecular data
    • …
    corecore