53 research outputs found

    The effects of previous-year corn hybrid and cropping system on current-year corn hybrids in second year corn

    Get PDF
    Grain yields decrease when corn (Zea mays L.) follows corn compared to corn grown in rotation with other crops. The factors that decrease grain yield of corn following corn are not well understood, and limit recommendations available to corn growers. Our objectives were to determine (i) if plant population, moisture, and yield of 2nd year corn are affected by the previous-year corn hybrid, (ii) evaluate if continued use of single hybrid over two growing seasons influences grain yield, and (iii) compare 2nd year corn yields to corn grown in rotation with soybean. The experiment was conducted at six Iowa locations in 2008 and 2009; three locations were in the Northern region of Iowa and three in the south. Three corn hybrids were planted in 18 m2 blocks as the main plots in the first year, followed by 12 hybrids planted on each of the main plots in the second year. The same 12 hybrids were planted into a nearby field on soybean residue at each location in 2008, but established as a main plot for 2009. Plant population was not influenced by the three previous-year corn hybrids. Plant populations were greater when corn followed soybean compared to 2nd year corn. Grain moisture content was not influenced by crop rotation or previous-year corn hybrid. Previous-year corn residue did not impact grain yield of the current-year hybrid, and the continued use of single hybrid over multiple growing seasons showed no influence on grain yield. Cropping system influenced grain yield in 2009, within both regions. Second-year corn yields were 11% and 14% less in the north and south regions, respectively, compared to corn rotated with soybean. Previous-year corn hybrid did not influence plant population, grain yield, or grain moisture. The influence of previous-year corn hybrid on the root and plant growth of the current-year hybrids is not well understood and may account for the decrease in grain yield. The objectives the second study were to determine (i) if current-year corn grain yields, root, and plant biomass were influenced by previous-year hybrid and/or cropping system (ii) if there are differences in plant and root biomass among modern commercial corn hybrids (iii) if root and plant biomass are correlated with grain yield. In 2008 and 2009, root and plant biomass studies were conducted at two Iowa State University research and demonstration farms. Experimental design and corn hybrids were the same as the grain yield study. At each location, root and plant biomass samplings were conducted at four different sample dates: V4, V12, VT, and R6. After sampling, roots were washed, dried, and weighed while plants were dried and weighed. Root and plant biomass were compiled and calculated for comparison. Overall, previous-year corn hybrid/cropping system did not influence root or plant biomass; however, plant biomass was greater when corn followed soybean compared to 2nd year corn at Kanawha and Ames in 2009. Current-year hybrids were variable and did not indicate strong differences in root or plant biomass. Root biomass was not correlated with grain yield within any sample date. Plant biomass was correlated with grain yield at sample date 2 and 4 in Kanawha (2009). Root to shoot correlations were strong within all sample dates indicating that root growth is correlated to shoot growth throughout the growing season. Root and plant biomass are not influenced by the previous-year hybrid and are poor indicators of final grain yield

    The role of role theory in International Political Economy

    Get PDF
    This article demonstrates the benefits of using a role theory approach in the field of International Political Economy (IPE) by demonstrating the benefits of role theory relative to variants of the social constructivist paradigm, especially vis-à-vis identity based accounts of IPE. This article also documents why and how role theory has always had a home in IPE even before the constructivist revolution in the 1990s. The social interactionist dimension in the work of Herbert Mead and his notion of a general other are linked to the relational ideas of friendship and impartial spectator present in the works of the founding father of classical political economy, Adam Smith. These similar ideas about the self and their surrounding social environment is a useful starting point to locate role theory in IPE and demonstrate its analytical advantages within social constructivism. After showing the “forgotten” place role theory has always had in IPE, the article illustrates the potential of using a role theory approach within the field of IPE through an illustrative analysis of the Greek economic crisis

    Linking Symptom Inventories using Semantic Textual Similarity

    Full text link
    An extensive library of symptom inventories has been developed over time to measure clinical symptoms, but this variety has led to several long standing issues. Most notably, results drawn from different settings and studies are not comparable, which limits reproducibility. Here, we present an artificial intelligence (AI) approach using semantic textual similarity (STS) to link symptoms and scores across previously incongruous symptom inventories. We tested the ability of four pre-trained STS models to screen thousands of symptom description pairs for related content - a challenging task typically requiring expert panels. Models were tasked to predict symptom severity across four different inventories for 6,607 participants drawn from 16 international data sources. The STS approach achieved 74.8% accuracy across five tasks, outperforming other models tested. This work suggests that incorporating contextual, semantic information can assist expert decision-making processes, yielding gains for both general and disease-specific clinical assessment

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    The US Program in Ground-Based Gravitational Wave Science: Contribution from the LIGO Laboratory

    Get PDF
    Recent gravitational-wave observations from the LIGO and Virgo observatories have brought a sense of great excitement to scientists and citizens the world over. Since September 2015,10 binary black hole coalescences and one binary neutron star coalescence have been observed. They have provided remarkable, revolutionary insight into the "gravitational Universe" and have greatly extended the field of multi-messenger astronomy. At present, Advanced LIGO can see binary black hole coalescences out to redshift 0.6 and binary neutron star coalescences to redshift 0.05. This probes only a very small fraction of the volume of the observable Universe. However, current technologies can be extended to construct "3rd Generation" (3G) gravitational-wave observatories that would extend our reach to the very edge of the observable Universe. The event rates over such a large volume would be in the hundreds of thousands per year (i.e. tens per hour). Such 3G detectors would have a 10-fold improvement in strain sensitivity over the current generation of instruments, yielding signal-to-noise ratios of 1000 for events like those already seen. Several concepts are being studied for which engineering studies and reliable cost estimates will be developed in the next 5 years

    Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

    Get PDF
    During their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100 M ⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93 Gpc−3yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits

    First low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO data

    Get PDF
    We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7 [1/root Hz]. At the frequency of best strain sensitivity, near 100 Hz, we set 90% confidence upper limits of 1.8 x 10(-25). At the low end of our frequency range, 20 Hz, we achieve upper limits of 3.9 x 10(-24). At 55 Hz we can exclude sources with ellipticities greater than 10(-5) within 100 pc of Earth with fiducial value of the principal moment of inertia of 10(38) kg m(2)

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

    Get PDF
    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
    corecore