1,409 research outputs found
Wheat take-all (1997)
Take-all is a disease of the roots, crown, and stem base of wheat. It interrupts plant development and may seriously suppress yields. A common problem of winter wheat in North America, Take-all occurs in Missouri especially under cool, damp conditions. The name originated in Australia in the middle of the last century when the disease 'took all' seedlings it attacked. In Missouri the disease seldom affects seedlings but more commonly attacks wheat plants at the tillering stage. This publication provides a description of the disease as well as some tips on how to control it
This We Believe, This We Do: Performance-Based Assessment in Middle Level Teacher Education
To assist institutions in developing high quality middle level teacher preparation programs, five veteran members of the NCATE/NMSA Program Review Board have identified more than 75 performance-based assessments directly correlated with the seven NMSA Standards for Teacher Preparation. In this article, 14 of these assessments are described in detail along with a sampling of rubrics. In addition, authors reveal their own challenges writing program reports as well as gaining stakeholder’s buy-in to performance-based assessment systems at their own institutions
Headspace analysis of mesothelioma cell lines differentiates biphasic and epithelioid sub-types.
Malignant mesothelioma (MM) is an incurable cancer. MM is often misdiagnosed, with a poor 5-year survival and limited treatment options. The discovery of endogenous volatile organic compounds (VOCs) is required in order to accelerate the development of a breath test as an alternative to conventional MM diagnosis. For the first time, this study used solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) to identify VOCs released directly from the biphasic MM cell line MSTO-211H and the epithelioid MM cell line NCI-H28 as well as the non-malignant mesothelial cell line MET-5A. Multivariate statistical analysis showed separation between MSTO-211H, NCI-H28 and MET-5A results. 2-ethyl-1-hexanol was significantly increased in both MSTO-211H and NCI-H28 cells compared to MET-5A controls. In addition, ethyl propionate and cyclohexanol were significantly increased in MSTO-211H cells and dodecane was significantly increased in NCI-H28 cells. This is the first study reporting headspace analysis of these MM cell lines and the first to consider the effects of mesothelioma sub-type on VOC profile. Current results further highlight the potential for a diagnostic mesothelioma breath test as well as providing proof of concept for the differentiation between biphasic and epithelioid mesothelioma based on VOC profiles
Gravity Spy: Integrating Advanced LIGO Detector Characterization, Machine Learning, and Citizen Science
(abridged for arXiv) With the first direct detection of gravitational waves,
the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) has
initiated a new field of astronomy by providing an alternate means of sensing
the universe. The extreme sensitivity required to make such detections is
achieved through exquisite isolation of all sensitive components of LIGO from
non-gravitational-wave disturbances. Nonetheless, LIGO is still susceptible to
a variety of instrumental and environmental sources of noise that contaminate
the data. Of particular concern are noise features known as glitches, which are
transient and non-Gaussian in their nature, and occur at a high enough rate so
that accidental coincidence between the two LIGO detectors is non-negligible.
In this paper we describe an innovative project that combines crowdsourcing
with machine learning to aid in the challenging task of categorizing all of the
glitches recorded by the LIGO detectors. Through the Zooniverse platform, we
engage and recruit volunteers from the public to categorize images of glitches
into pre-identified morphological classes and to discover new classes that
appear as the detectors evolve. In addition, machine learning algorithms are
used to categorize images after being trained on human-classified examples of
the morphological classes. Leveraging the strengths of both classification
methods, we create a combined method with the aim of improving the efficiency
and accuracy of each individual classifier. The resulting classification and
characterization should help LIGO scientists to identify causes of glitches and
subsequently eliminate them from the data or the detector entirely, thereby
improving the rate and accuracy of gravitational-wave observations. We
demonstrate these methods using a small subset of data from LIGO's first
observing run.Comment: 27 pages, 8 figures, 1 tabl
Dynamical decay of a massive multiple system in Orion KL?
We present absolute astrometry of 35 radio sources in the Orion Trapezium and
Becklin-Neugebauer/Kleinman-Low regions, obtained from Very Large Array
archival observations collected over a period of 15 years. By averaging the
results for all the sources, we estimate the mean absolute proper motion of
Orion to be --in Galactic coordinates-- = +2.1 0.2 mas
yr; = 0.1 0.2 mas yr. These values agree
remarkably well with those expected from the differential rotation of the Milky
Way. Subtraction of this mean motion from the individual measurements allows us
to register all proper motions to the rest frame of the Orion nebula, and
identify radio sources with large residual velocities. In the KL region, we
find three sources in this situation: the BN object, the radio source I, and
the radio counterpart of the infrared source n. All three objects appear to be
moving away from a common point where they must all have been located about 500
years ago. This suggests that all three sources were originally part of a
multiple massive stellar system that recently disintegrated as a result of a
close dynamicalComment: Accepted for publication in the Ap
Effects of Feeding a Novel Alfalfa Leaf Pellet Product (ProLEAF MAX) and Alfalfa Stems (ProFiber Plus) on Performance in the Feedlot and Carcass Quality of Beef Steers
Alfalfa is often included in the diets of beef animals; however, the nutrient content of alfalfa is variable depending on the region in which it is grown, climate, soil, and many other factors. The leaf portion of alfalfa has a less variable nutrient composition than the stem portion of the plant. The variability that is present in the alfalfa plant can make the development of total mixed rations of consistent nutrient content difficult. As such, the purpose of this study was to determine how the inclusion of fractionated alfalfa leaves and alfalfa stems impacts performance and carcass quality of finishing beef steers. Twenty-four steers were allocated to one of three treatments: a control group fed a typical finishing diet with alfalfa as the forage (CON; n = 8), a typical diet that replaced alfalfa with fractionated alfalfa leaf pellets and alfalfa stems (ProLEAF MAX™ + ProFiber Plus™; PLM+PFP; n = 8), or a typical diet that replaced alfalfa with alfalfa stems (PFP; n = 8) for 63 days. Steers were fed individually once daily, weighed every 14 days and ultrasound images were collected every 28 days. At the end of the feeding trial, steers were harvested at a commercial facility and carcass data was obtained. Analysis of dry matter intake demonstrated that steers receiving the PFP and CON diets consumed more feed (P \u3c 0.001) than steers consuming the PLM+PFP diet. Steers receiving the PLM+PFP diet gained less (P \u3c 0.001) weight than the steers receiving the other two dietary treatments. No differences (P \u3e 0.10) in feed efficiency or carcass characteristics were observed. Steers receiving the PFP diet had improved (P = 0.016) cost of gain (1.08 per kg) diet. Overall, our findings demonstrate that the inclusion of PFP in place of alfalfa hay in a finishing diet has the potential to improve cost of gain, without negatively affecting growth, performance, or carcass characteristics of finishing feedlot steers
Optimism and Risk of Incident Hypertension: A Target for Primordial Prevention
Aims
Optimism is associated with reduced cardiovascular disease risk; however, few prospective studies have considered optimism in relation to hypertension risk specifically. We investigated whether optimism was associated with a lower risk of developing hypertension in U.S. service members, who are more likely to develop high blood pressure early in life. We also evaluated race/ethnicity, sex and age as potential effect modifiers of these associations.
Methods
Participants were 103 486 hypertension-free U.S. Army active-duty soldiers (mean age 28.96 years, 61.76% White, 20.04% Black, 11.01% Hispanic, 4.09% Asian, and 3.10% others). We assessed optimism, sociodemographic characteristics, health conditions, health behaviours and depression status at baseline (2009–2010) via self-report and administrative records, and ascertained incident hypertension over follow-up (2010–2014) from electronic health records and health assessments. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), and adjusted models for a broad range of relevant covariates.
Results
Over a mean follow-up of 3.51 years, 15 052 incident hypertension cases occurred. The highest v. lowest optimism levels were associated with a 22% reduced risk of developing hypertension, after adjusting for all covariates including baseline blood pressure (HR = 0.78; 95% CI = 0.74–0.83). The difference in hypertension risk between the highest v. lowest optimism was also maintained when we excluded soldiers with hypertension in the first two years of follow-up and, separately, when we excluded soldiers with prehypertension at baseline. A dose–response relationship was evident with higher optimism associated with a lower relative risk (p \u3c 0.001). Higher optimism was consistently associated with a lower risk of developing hypertension across sex, age and most race/ethnicity categories.
Conclusions
In a diverse cohort of initially healthy male and female service members particularly vulnerable to developing hypertension, higher optimism levels were associated with reduced hypertension risk independently of sociodemographic and health factors, a particularly notable finding given the young and healthy population. Results suggest optimism is a health asset and a potential target for public health interventions
Use of Risk Models to Predict Death in the Next Year Among Individual Ambulatory Patients With Heart Failure
Importance: The clinical practice guidelines for heart failure recommend the use of validated risk models to estimate prognosis. Understanding how well models identify individuals who will die in the next year informs decision making for advanced treatments and hospice.
Objective: To quantify how risk models calculated in routine practice estimate more than 50% 1-year mortality among ambulatory patients with heart failure who die in the subsequent year.
Design, Setting, and Participants: Ambulatory adults with heart failure from 3 integrated health systems were enrolled between 2005 and 2008. The probability of death was estimated using the Seattle Heart Failure Model (SHFM) and the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk calculator. Baseline covariates were collected from electronic health records. Missing covariates were imputed. Estimated mortality was compared with actual mortality at both population and individual levels.
Main Outcomes and Measures: One-year mortality.
Results: Among 10930 patients with heart failure, the median age was 77 years, and 48.0% of these patients were female. In the year after study enrollment, 1661 patients died (15.9% by life-table analysis). At the population level, 1-year predicted mortality among the cohort was 9.7% for the SHFM (C statistic of 0.66) and 17.5% for the MAGGIC risk calculator (C statistic of 0.69). At the individual level, the SHFM predicted a more than 50% probability of dying in the next year for 8 of the 1661 patients who died (sensitivity for 1-year death was 0.5%) and for 5 patients who lived at least a year (positive predictive value, 61.5%). The MAGGIC risk calculator predicted a more than 50% probability of dying in the next year for 52 of the 1661 patients who died (sensitivity, 3.1%) and for 63 patients who lived at least a year (positive predictive value, 45.2%). Conversely, the SHFM estimated that 8496 patients (77.8%) had a less than 15% probability of dying at 1 year, yet this lower-risk end of the score range captured nearly two-thirds of deaths (n = 997); similarly, the MAGGIC risk calculator estimated a probability of dying of less than 25% for the majority of patients who died at 1 year (n = 914).
Conclusions and Relevance: Although heart failure risk models perform reasonably well at the population level, they do not reliably predict which individual patients will die in the next year
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Metabolic Risk Factors as Differential Predictors of Profiles of Neurocognitive Impairment Among Older HIV+ and HIV- Adults: An Observational Study.
ObjectiveNeurocognitive performance among older persons, including those living with HIV (people living with HIV [PLWH]), exhibits significant heterogeneity, suggesting subpopulations with differing profiles of neurocognitive impairment (NCI). Metabolic factors are associated with NCI, but their relationships to cluster-derived NCI profiles are unknown.MethodParticipants (144 PLWH and 102 HIV uninfected) aged 50+ years completed a neuropsychological battery assessing seven cognitive domains. Latent class analysis (LCA) identified NCI profiles separately by HIV serostatus and in a combined sample. Obtained classes were examined against the Montreal Cognitive Assessment (MoCA) and diagnoses of HIV-associated neurocognitive disorders (HAND). Multinomial regression identified metabolic predictors of classification.ResultsLCA identified three latent classes in each participant sample: Class1Multidomain NCI (high probability of impairment across multiple domains), Class 2Learning & Recall NCI (high probability of impairment in learning and recall), and Class 3NC Unimpaired (low probability of NCI across all domains). Severity of NCI implied by classes corresponded with MoCA scores and HAND diagnoses. In analyses on the combined sample, compared to HIV-uninfected individuals, PLWH were more likely to be in Class1Multidomain NCI. Among PLWH, those with dyslipidemia and hypertension had greater odds of classification in Class 1Multidomain NCI while those with central obesity had higher odds of classification in Class 2Learning & Recall NCI; metabolic syndrome approached significance as a differential predictor. Regardless of HIV status, individuals with diabetes were more likely to be in Class 1Multidomain NCI.ConclusionsMetabolic risk factors confer heightened risk of NCI in HIV infection. Interventions to reduce metabolic risk may improve neurocognitive outcomes among PLWH
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