Potential for Controlling the Spread of \u3ci\u3eCentaurea maculosa\u3c/i\u3e with Grass Competition

ABSTRACT.-Spotted knapweed (Centaurea maculosa Lam.) is a major rangeland and roadside weed of the northern Rocky Mountains. It is often found in plant communities dominated by Pseudoroegneria spicatum or Festuca idahoensis, but it rarely invades roadsides dominated by Bromus inerrnis Leyss. Aboveground biomass of the 3 grass species grown in mixture with Centaurea was compared to growth in monoculture at a range of nitrogen input levels. The results suggest that Bromus is capable of suppressing the growth of Centaurea with the degree of suppression increasing with increasing nitrogen levels. The 2 native grasses had no impact on Centaurea under the controlled environment conditions of this study

The population dynamics and growth of salmonberry (Rubus spectabilis) and thimbleberry (Rubus parviflorus)

Salmonberry (Rubus spectabilis) and thimbleberry (Rubus parviflorus) are clonal shrub species common to reforestation sites in the Oregon Coast Range. These species have economic importance, because they reduce conifer seedling growth and survival. A population modeling approach was used to facilitate study of the biology of these species and to assess management practices. A generic Rubus transition matrix model was developed from the literature and used to generate hypotheses and focus research on demographic processes governing population dynamics. Sensitivity analysis on the model indicated that transition from basal buds to sprouts, shoot survival, sprout transition to mature vegetative shoots, and basal bud production on mature vegetative shoots were important processes influencing population growth. High basal bud production potential and sprout survival and growth relative to seedlings indicated that populations should be dominated by sprouts rather than seedlings. Density-biomass relationships conformed to the constant final yield theory. The influence of density on demographic processes was inconsistent over time and sites indicating that the intensity of competition is not constant. Therefore, density-dependence is a dynamic population growth regulating mechanism. The model was refined by incorporating the species specific influence of phenology, environments at different sites, and intraspecific density on demographic processes. Population simulations were compared with observations on planted and adjacent wild populations for the first three growing seasons. An average of 71% of the variation in observed planted population and 81% in wild population shoot dynamics was accounted for by the simulations. Canopy cover and height growth were simulated in the model as a function of density. Simulations of a herbicide treatment and manual cutting demonstrated the utility of the model for evaluating salmonberry and thimbleberry management tactics

Multiple prior concussions are associated with symptoms in high school athletes

Objectives: The purpose of this study was to evaluate the association of prior concussion on baseline computerized neurocognitive testing in a large cohort of high school athletes. Methods: This is a retrospective cohort study of student athletes from 49 Maine High Schools in 2010 who underwent baseline computerized neurocognitive evaluation with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®). As part of the ImPACT®, subjects reported a prior history of concussion as well as demographic information and a symptom questionnaire. We used linear regression to evaluate the association of prior concussion with baseline: (1) ImPACT® composite scores; and (2) symptom scores. Results: Six thousand seventy-five subjects were included in the study, of whom 57% were boys. The majority of student athletes (85.3%) reported no prior history of concussion while 4.6% reported having sustained two or more prior concussions. On simple linear regression, increasing number of concussions was related to worse performance in verbal memory (P = 0.039) and greater symptoms scores (P < 0.001). On multivariate modeling, only the association with baseline symptoms remained (P < 0.001). Other factors associated with baseline symptom reporting in the multivariate model included mental health history, headache/migraine history, gender, developmental and/or learning problems, and number of prior concussions. Interpretation In this large-scale, retrospective survey study, history of multiple prior concussions was associated with higher symptom burden but not baseline computerized neurocognitive testing. The association between baseline symptom reporting and clinical and demographic factors was greater than the association with a history of multiple concussions

Examining Criteria for Defining Persistent Post-Concussion Symptoms in Children and Adolescents

Researchers operationalize persistent post-concussion symptoms in children and adolescents using varied definitions. Many pre-existing conditions, personal characteristics, and current health issues can affect symptom endorsement rates in the absence of, or in combination with, a recent concussion, and the use of varied definitions can lead to differences in conclusions about persistent symptoms and recovery across studies. This study examined how endorsement rates varied by 14 different operational definitions of persistent post-concussion symptoms for uninjured boys and girls with and without pre-existing or current health problems. This cross-sectional study included a large sample (age range: 11–18) of girls (n = 21,923) and boys (n = 26,556) without a recent concussion who completed the Post-Concussion Symptom Scale at preseason baseline. Endorsements rates varied substantially by definition, health history, and current health issues. The most lenient definition (i.e., a single mild symptom) was endorsed by most participants (54.5% of boys/65.3% of girls). A large portion of participants with pre-existing mental health problems (42.7% of boys/51.5% of girls), current moderate psychological distress (70.9% of boys/72.4% of girls), and insufficient sleep prior to testing (33.4% of boys/47.6% of girls) endorsed symptoms consistent with mild ICD-10 postconcussional syndrome; whereas participants with no current or prior health problems rarely met this definition (1.6% of boys/1.6% of girls). The results illustrate the tremendous variability in the case definitions of persistent symptoms and the importance of harmonizing definitions across future studies

Proceedings - U.S.A Agroecology Summit 2023

This docket is a memory of the meeting held in Kansas City from May 22-25 called the 2023 USA Agroecology Summit and contains all the documents generated before, during, and after the meeting

Global Invader Impact Network (GIIN): toward standardized evaluation of the ecological impacts of invasive plants

Terrestrial invasive plants are a global problem and are becoming ubiquitous components of most ecosystems. They are implicated in altering disturbance regimes, reducing biodiversity, and changing ecosystem function, sometimes in profound and irreversible ways. However, the ecological impacts of most invasive plants have not been studied experimentally, and most research to date focuses on few types of impacts, which can vary greatly among studies. Thus, our knowledge of existing ecological impacts ascribed to invasive plants is surprisingly limited in both breadth and depth. Our aim was to propose a standard methodology for quantifying baseline ecological impact that, in theory, is scalable to any terrestrial plant invader (e.g., annual grasses to trees) and any invaded system (e.g., grassland to forest). The Global Invader Impact Network (GIIN) is a coordinated distributed experiment composed of an observational and manipulative methodology. The protocol consists of a series of plots located in (1) an invaded area; (2) an adjacent removal treatment within the invaded area; and (3) a spatially separate uninvaded area thought to be similar to pre-invasion conditions of the invaded area. A standardized and inexpensive suite of community, soil, and ecosystem metrics are collected allowing broad comparisons among measurements, populations, and species. The method allows for one-time comparisons and for long-term monitoring enabling one to derive information about change due to invasion over time. Invader removal plots will also allow for quantification of legacy effects and their return rates, which will be monitored for several years. GIIN uses a nested hierarchical scale approach encompassing multiple sites, regions, and continents. Currently, GIIN has network members in six countries, with new members encouraged. To date, study species include representatives of annual and perennial grasses; annual and perennial forbs; shrubs; and trees. The goal of the GIIN framework is to create a standard yet flexible platform for understanding the ecological impacts of invasive plants, allowing both individual and synthetic analyses across a range of taxa and ecosystems. If broadly adopted, this standard approach will offer unique insight into the ecological impacts of invasive plants at local, regional, and global scales.Fil: Barney, Jacob N. Virginia Tech. Department of Plant Pathology, Physiology, and Weed Science; Estados UnidosFil: Tekiela, Daniel R. Virginia Tech. Department of Plant Pathology, Physiology, and Weed Science; Estados UnidosFil: Barrios Garcia Moar, Maria Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. CENAC-APN; ArgentinaFil: Dimarco, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas-Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo de Ecología de Poblaciones de Insectos; ArgentinaFil: Hufbauer, Ruth A. Colorado State University. Department of Bioagricultural Sciences and Pest Management and Graduate Degree Program in Ecology; Estados UnidosFil: Leipzig-Scott, Peter. Colorado State University. Department of Bioagricultural Sciences and Pest Management and Graduate Degree Program in Ecology; Estados UnidosFil: Nuñez, Martin A. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad del Comahue. INIBIOMA. Laboratorio de Ecotono; ArgentinaFil: Pauchard, Anibal. Universidad de Concepción. Facultad de Ciencias Forestales. Laboratorio de Invasiones Biolóogicas; Chile. Institute of Ecology and Biodiversity (IEB); ChileFil: Pysek, Petr. The Czech Academy of Sciences. Institute of Botany. Department of Invasion Ecology; República Checa. Charles University in Prague. Faculty of Science. Department of Ecology; República ChecaFil: Viıtkov, Michaela. The Czech Academy of Sciences. Institute of Botany. Department of Invasion Ecology; República ChecaFil: Maxwell, Bruce D. Montana State University. Department of Land Resources and Environmental Sciences; Estados Unido

Physical and mental health comorbidity is common in people with multiple sclerosis: nationally representative cross-sectional population database analysis

&lt;b&gt;Background&lt;/b&gt; Comorbidity in Multiple Sclerosis (MS) is associated with worse health and higher mortality. This study aims to describe clinician recorded comorbidities in people with MS. &lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; 39 comorbidities in 3826 people with MS aged ≥25 years were compared against 1,268,859 controls. Results were analysed by age, gender, and socioeconomic status, with unadjusted and adjusted Odds Ratios (ORs) calculated using logistic regression. &lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; People with MS were more likely to have one (OR 2.44; 95% CI 2.26-2.64), two (OR 1.49; 95% CI 1.38-1.62), three (OR 1.86; 95% CI 1.69-2.04), four or more (OR 1.61; 95% CI 1.47-1.77) non-MS chronic conditions than controls, and greater mental health comorbidity (OR 2.94; 95% CI 2.75-3.14), which increased as the number of physical comorbidities rose. Cardiovascular conditions, including atrial fibrillation (OR 0.49; 95% CI 0.36-0.67), chronic kidney disease (OR 0.51; 95% CI 0.40-0.65), heart failure (OR 0.62; 95% CI 0.45-0.85), coronary heart disease (OR 0.64; 95% CI 0.52-0.71), and hypertension (OR 0.65; 95% CI 0.59-0.72) were significantly less common in people with MS. &lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusion&lt;/b&gt; People with MS have excess multiple chronic conditions, with associated increased mental health comorbidity. The low recorded cardiovascular comorbidity warrants further investigation

Gemini Planet Imager observational calibrations XV: instrument calibrations after six years on sky

The Gemini Planet Imager (GPI) is a high-contrast adaptive optics instrument designed to detect and characterize substellar companions and circumstellar debris disks around nearby young stars using infrared integral field spectroscopy and polarimetry. GPI has been in routine operations at Gemini South for the past six years. Because precise astrometry and photometry of exoplanets is critical to GPI's science, we undertook extensive efforts both in-lab and on-sky to refine the astrometric and photometric calibration of the instrument. We describe revisions to the GPI Data Reduction Pipeline (DRP) that account for these revised calibrations, and that fix several issues identified over the previous six years, including some subtle issues affecting astrometric calibrations caused by a drift of the instrument’s clock. These calibrations are critical for the interpretation of observations obtained with GPI, and for a comparison with measurements from other high-contrast imaging instruments

Gemini Planet Imager observational calibrations XV: instrument calibrations after six years on sky

The Gemini Planet Imager (GPI) is a high-contrast adaptive optics instrument designed to detect and characterize substellar companions and circumstellar debris disks around nearby young stars using infrared integral field spectroscopy and polarimetry. GPI has been in routine operations at Gemini South for the past six years. Because precise astrometry and photometry of exoplanets is critical to GPI's science, we undertook extensive efforts both in-lab and on-sky to refine the astrometric and photometric calibration of the instrument. We describe revisions to the GPI Data Reduction Pipeline (DRP) that account for these revised calibrations, and that fix several issues identified over the previous six years, including some subtle issues affecting astrometric calibrations caused by a drift of the instrument’s clock. These calibrations are critical for the interpretation of observations obtained with GPI, and for a comparison with measurements from other high-contrast imaging instruments

Dynamical Mass Measurement of the Young Spectroscopic Binary V343 Normae AaAb Resolved With the Gemini Planet Imager

We present new spatially resolved astrometry and photometry from the Gemini Planet Imager of the inner binary of the young multiple star system V343 Normae, which is a member of the beta Pictoris moving group. V343 Normae comprises a K0 and mid-M star in a ~4.5 year orbit (AaAb) and a wide 10" M5 companion (B). By combining these data with archival astrometry and radial velocities we fit the orbit and measure individual masses for both components of M_Aa = 1.10 +/- 0.10 M_sun and M_Ab = 0.290 +/- 0.018 M_sun. Comparing to theoretical isochrones, we find good agreement for the measured masses and JHK band magnitudes of the two components consistent with the age of the beta Pic moving group. We derive a model-dependent age for the beta Pic moving group of 26 +/- 3 Myr by combining our results for V343 Normae with literature measurements for GJ 3305, which is another group member with resolved binary components and dynamical masses.Comment: 12 pages, 7 figures. Accepted to A