22 research outputs found

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015 : a systematic analysis for the Global Burden of Disease Study 2015

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    Background Improving survival and extending the longevity of life for all populations requires timely, robust evidence on local mortality levels and trends. The Global Burden of Disease 2015 Study (GBD 2015) provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015. These results informed an in-depth investigation of observed and expected mortality patterns based on sociodemographic measures. Methods We estimated all-cause mortality by age, sex, geography, and year using an improved analytical approach originally developed for GBD 2013 and GBD 2010. Improvements included refinements to the estimation of child and adult mortality and corresponding uncertainty, parameter selection for under-5 mortality synthesis by spatiotemporal Gaussian process regression, and sibling history data processing. We also expanded the database of vital registration, survey, and census data to 14 294 geography-year datapoints. For GBD 2015, eight causes, including Ebola virus disease, were added to the previous GBD cause list for mortality. We used six modelling approaches to assess cause-specific mortality, with the Cause of Death Ensemble Model (CODEm) generating estimates for most causes. We used a series of novel analyses to systematically quantify the drivers of trends in mortality across geographies. First, we assessed observed and expected levels and trends of cause-specific mortality as they relate to the Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Second, we examined factors affecting total mortality patterns through a series of counterfactual scenarios, testing the magnitude by which population growth, population age structures, and epidemiological changes contributed to shifts in mortality. Finally, we attributed changes in life expectancy to changes in cause of death. We documented each step of the GBD 2015 estimation processes, as well as data sources, in accordance with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, life expectancy from birth increased from 61.7 years (95% uncertainty interval 61.4-61.9) in 1980 to 71.8 years (71.5-72.2) in 2015. Several countries in sub-Saharan Africa had very large gains in life expectancy from 2005 to 2015, rebounding from an era of exceedingly high loss of life due to HIV/AIDS. At the same time, many geographies saw life expectancy stagnate or decline, particularly for men and in countries with rising mortality from war or interpersonal violence. From 2005 to 2015, male life expectancy in Syria dropped by 11.3 years (3.7-17.4), to 62.6 years (56.5-70.2). Total deaths increased by 4.1% (2.6-5.6) from 2005 to 2015, rising to 55.8 million (54.9 million to 56.6 million) in 2015, but age-standardised death rates fell by 17.0% (15.8-18.1) during this time, underscoring changes in population growth and shifts in global age structures. The result was similar for non-communicable diseases (NCDs), with total deaths from these causes increasing by 14.1% (12.6-16.0) to 39.8 million (39.2 million to 40.5 million) in 2015, whereas age-standardised rates decreased by 13.1% (11.9-14.3). Globally, this mortality pattern emerged for several NCDs, including several types of cancer, ischaemic heart disease, cirrhosis, and Alzheimer's disease and other dementias. By contrast, both total deaths and age-standardised death rates due to communicable, maternal, neonatal, and nutritional conditions significantly declined from 2005 to 2015, gains largely attributable to decreases in mortality rates due to HIV/AIDS (42.1%, 39.1-44.6), malaria (43.1%, 34.7-51.8), neonatal preterm birth complications (29.8%, 24.8-34.9), and maternal disorders (29.1%, 19.3-37.1). Progress was slower for several causes, such as lower respiratory infections and nutritional deficiencies, whereas deaths increased for others, including dengue and drug use disorders. Age-standardised death rates due to injuries significantly declined from 2005 to 2015, yet interpersonal violence and war claimed increasingly more lives in some regions, particularly in the Middle East. In 2015, rotaviral enteritis (rotavirus) was the leading cause of under-5 deaths due to diarrhoea (146 000 deaths, 118 000-183 000) and pneumococcal pneumonia was the leading cause of under-5 deaths due to lower respiratory infections (393 000 deaths, 228 000-532 000), although pathogen-specific mortality varied by region. Globally, the effects of population growth, ageing, and changes in age-standardised death rates substantially differed by cause. Our analyses on the expected associations between cause-specific mortality and SDI show the regular shifts in cause of death composition and population age structure with rising SDI. Country patterns of premature mortality (measured as years of life lost [YLLs]) and how they differ from the level expected on the basis of SDI alone revealed distinct but highly heterogeneous patterns by region and country or territory. Ischaemic heart disease, stroke, and diabetes were among the leading causes of YLLs in most regions, but in many cases, intraregional results sharply diverged for ratios of observed and expected YLLs based on SDI. Communicable, maternal, neonatal, and nutritional diseases caused the most YLLs throughout sub-Saharan Africa, with observed YLLs far exceeding expected YLLs for countries in which malaria or HIV/AIDS remained the leading causes of early death. Interpretation At the global scale, age-specific mortality has steadily improved over the past 35 years; this pattern of general progress continued in the past decade. Progress has been faster in most countries than expected on the basis of development measured by the SDI. Against this background of progress, some countries have seen falls in life expectancy, and age-standardised death rates for some causes are increasing. Despite progress in reducing age-standardised death rates, population growth and ageing mean that the number of deaths from most non-communicable causes are increasing in most countries, putting increased demands on health systems. Copyright (C) The Author(s). Published by Elsevier Ltd.Peer reviewe

    <i>NbTOM1</i> transcript levels and virus accumulation with overexpression or silencing of <i>NbTOM1</i> in <i>Nicotiana</i><i>benthamiana</i>.

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    <p>(A) The transcriptional levels of <i>NbTOM1</i> were detected in mock inoculation buffer, HLSV, TMV, HLSV+TMV (100:1) and HLSV+TMV (1:1) co-infected plants. The viral RNA levels of HLSV and TMV were determined using quantitative real-time RT-PCR with primer sequences corresponding to the coat protein genes in HLSV, or TMV or co-infected leaves. (B and C) The transcriptional levels of <i>NbTOM1</i> were detected in <i>NbTOM1</i>overexpressed or silenced leaves. The viral RNA levels were detected in plants first infiltrated with pGreen orpGreen-<i>NbTOM1</i> (for overexpression), and pGreen or pGreen-<i>NbTOM1</i>(nt1-581) (for silencing), followed by single virus (HLSV or TMV) infection or co-infection(HLSV+TMV) at 40 h post inoculation (hpi). (D) The coat proteins of HLSV and TMV were detected by western blot in <i>NbTOM1</i>overexpressed or silenced leaves which were subsequently infected with single virus (HLSV or TMV) or co-infected with HLSV+TMV at 5 dpi (details see Materials & Methods). Total protein from mock buffer inoculated <i>N</i><i>. benthamiana</i> leaves was used as the negative control, while the total protein from HLSV or TMV infected leave samples which were confirmed earlier were used as positive controls.</p

    Genome organizations of HLSV and TMV and detection of viral RNA and protein levels in cross protection.

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    <p>(<b>A</b>) Genome organization of HLSV and TMV. Transcriptional level of HLSV (<b>B</b>) or TMV (<b>C</b>) gRNA/total viral RNA determined by quantitative real-time RT-PCR and translational level of CPs by western blot (<b>B</b> and <b>C</b>). Significant differences were calculated using the Student’s <i>t</i>-test, * and ** indicate significance at the 0.05 and 0.01 levels of confidence, respectively.</p

    Cross protection between HLSV and TMV and its symptom expressions in <i>Nicotiana</i><i>benthamiana</i>.

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    <p>(A) The number of surviving <i>N</i><i>. benthamiana</i> plants inoculated with mock buffer, HLSV, TMV and HLSV+TMV at different time points. All plants survived mock and HLSV inoculation. No plants survived inoculation with TMV. Half of the TMV infected <i>N</i><i>. benthamiana</i> (pre-inoculated with HLSV 12 days earlier) survived at 40 dpi. (B) The top, middle and bottom rows showed the top, close-ups and the side views of mock buffer (M), HLSV (H), TMV (T) and HLSV+TMV (H+T) inoculated <i>N</i><i>. benthamiana</i> plants, respectively. The red dotted line boxes in the top panels highlighted the close-up areas shown in the middle panels. Typical symptoms (red arrows pointing to) of inoculated <i>N</i><i>. benthamiana</i> plants are shown in the middle row. Among them, panel M, no symptom; panel H, mild leaf puckering at 20 dpi; panel T, systemic necrosis (plant death) at 8 dpi; panel H+T, mild mosaic symptoms at 20 dpi, plant height was shorter than H but taller than T inoculated plants. All scale bars represent 1 cm.</p

    Transcriptional levels of selected genes in cross protection.

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    <p>The transcriptional levels of <i>NbARP1</i>, <i>NbCaM3</i>, <i>NbCP2</i>, <i>NbPI</i>, <i>NbVPE1α</i>, <i>NbACO</i>, <i>NbSAR8.2m</i>, <i>NbWIPK</i>, <i>NbWRKY8</i>, <i>NbTOM1, NbHsp101</i> and <i>NbAGO4-2</i>.</p

    Hierarchical cluster analysis of transcriptional profiles and gene ontology analysis.

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    <p>(A) A hierarchical cluster analysis of transcriptional profiles for 24237 genes or ESTs of <i>Nicotiana</i><i>benthamiana</i> inoculated with inoculation buffer (mock), HLSV, HLSV+TMV (plants cross protected by pre-inoculation of HLSV 12 days prior to TMV challenge inoculation). The 3 columns correspond to biological repeats after inoculation with buffer (mock), HLSV, HLSV+TMV and TMV (at 12 dpi for mock and HLSV, and 3 dpi for HLSV+TMV and TMV which is equal to 15 dpi of HLSV). The clustering on the top of hierarchical map represents the differences among samples and biological repeats, while the left clustering is based on the expression levels of different genes. (B) Venn diagram of genes in response to HLSV infection and cross protection. (C) HLSV infection. (D) Gene ontology (GO) analysis of genes in response to HLSV+TMV infection (cross protection).</p
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