57 research outputs found

    The effect of injury in imitation of hail damage on the development of small grain

    Get PDF
    1. Five types of injury were inflicted on oats, barley and winter wheat at weekly intervals from May 11 to July 6. 2. Complete destruction of above ground parts increased the percentage of injury from 10 percent for oats, 43 percent for barley and 70 percent for wheat on May 11 to total loss for oats on June 15, barley on June 8 and wheat on June 1. 3. Cutting off all leaves above the growing point reduced yields about in proportion to the percentage of leaf area removed at each weekly interval. 4. Whipping severely enough to break all plants resulted in increasing the percentage of injury for oats from 10 percent on May 11 to 69 percent on June 15, for barley from 22 percent on May 11 to 72 percent on June 15, and for wheat from 25 percent on May 11 to 77 percent on June 15. 5. Bruising the developing heads before they had emerged reduced the yield of oats 10 percent on June 8, 8 percent on June 15 and 10 percent on June 22. Barley yields were reduced 25 percent as a result of this injury when inflicted on June 8, 10 percent on June 15 and 51 percent on June 22. Wheat yields were reduced 9 percent for May 25, 10 percent for June 1, 13 percent for June 8 and 20 percent for June 15. 6. Bruising the heads apparently increased the amount of sterile spikelets but was not the only cause of this condition. 7. Breaking the stems about the middle, so that the heads hung straight down, reduced yields progressively less from early in June until the grain was mature. Yields of oats were reduced at succeeding weekly intervals from June 8 to July 6, 47 percent, 37 percent, 31 percent, 24 percent and 12 percent, respectively, and barley for the same periods, 50 percent, 28 percent, 28 percent. 12 percent and 11 percent. This injury to wheat at weekly intervals from June 1 to June 29 reduced yields 44 percent, 42 percent, 31 percent, 14 percent and 8 percent, respectively

    Popcorn... Its production, processing and utilization

    Get PDF
    This is a brief summary of many years of research on all phases of the popcorn industry. Anyone wanting more detailed information on any of the topics mentioned should write the Agronomy Department, Iowa State University, Ames, Iowa. The early history of popcorn is clouded. It is generally agreed that corn originated in the New World— along with popcorn and other subspecies including dent, flint, flour and sweetcorn. Some students of the origin of corn contend that popcorn was one of the first— if not the first— subspecies to evolve from, wild grasses from which corn may have descended. In recent years archeologists have unearthed specimens which closely resemble a small-eared type of popcorn which we have today

    Book Reviews

    Get PDF

    The Roots of Diversity: Below Ground Species Richness and Rooting Distributions in a Tropical Forest Revealed by DNA Barcodes and Inverse Modeling

    Get PDF
    F. Andrew Jones is with the Smithsonian Tropical Research Institute, David L. Erickson is with the Smithsonian Institution, Moises A. Bernal is with the Smithsonian Tropical Research Institute and UT Austin, Eldredge Bermingham is with the Smithsonian Tropical Research Institute, W. John Kress is with the Smithsonian Institution, Edward Allen Herre is with the Smithsonian Tropical Research Institute, Helene C. Muller-Landau is with the Smithsonian Tropical Research Institute, Benjamin L. Turner is with the Smithsonian Tropical Research Institute.Background -- Plants interact with each other, nutrients, and microbial communities in soils through extensive root networks. Understanding these below ground interactions has been difficult in natural systems, particularly those with high plant species diversity where morphological identification of fine roots is difficult. We combine DNA-based root identification with a DNA barcode database and above ground stem locations in a floristically diverse lowland tropical wet forest on Barro Colorado Island, Panama, where all trees and lianas >1 cm diameter have been mapped to investigate richness patterns below ground and model rooting distributions. Methodology/Principal Findings -- DNA barcode loci, particularly the cpDNA locus trnH-psba, can be used to identify fine and small coarse roots to species. We recovered 33 species of roots from 117 fragments sequenced from 12 soil cores. Despite limited sampling, we recovered a high proportion of the known species in the focal hectare, representing approximately 14% of the measured woody plant richness. This high value is emphasized by the fact that we would need to sample on average 13 m2 at the seedling layer and 45 m2 for woody plants >1 cm diameter to obtain the same number of species above ground. Results from inverse models parameterized with the locations and sizes of adults and the species identifications of roots and sampling locations indicates a high potential for distal underground interactions among plants. Conclusions -- DNA barcoding techniques coupled with modeling approaches should be broadly applicable to studying root distributions in any mapped vegetation plot. We discuss the implications of our results and outline how second-generation sequencing technology and environmental sampling can be combined to increase our understanding of how root distributions influence the potential for plant interactions in natural ecosystems.FAJ acknowledges the support of a Tupper postdoctoral fellowship in tropical biology and the National Science Foundation (DEB 0453665). Funding was provided by the Smithsonian Institution Global Earth Observatory, the Smithsonian Tropical Research Institute/Center for Tropical Forest Sciences endowment fund, and the Smithsonian Tropical Research Institute/Frank Levinson fund. We would like to thank Autoridad Nacional del Ambiente and the Smithsonian Tropical Research Institute for processing research permits. We thank S. Hubbell and R. Condit for access to plot data, S. Schnitzer for liana census data (NSF DEB 0613666), and L. Comita and S. Hubbell for access to seedling data (NSF DEB 0075102 and DEB 0823728). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Marine Scienc

    A multidisciplinary approach to severe bronchopulmonary dysplasia is associated with resolution of pulmonary hypertension

    Get PDF
    ObjectiveTo describe our multidisciplinary bronchopulmonary dysplasia (BPD) consult team's systematic approach to BPD associated pulmonary hypertension (PH), to report our center outcomes, and to evaluate clinical associations with outcomes.Study designRetrospective cohort of 60 patients with BPD-PH who were referred to the Seattle Children's Hospital BPD team from 2018 to 2020. Patients with critical congenital heart disease were excluded. Demographics, comorbidities, treatments, closure of hemodynamically relevant intracardiac shunts, and clinical outcomes including time to BPD-PH resolution were reviewed.ResultsMedian gestational age of the 60 patients was 25 weeks (IQR: 24–26). 20% were small for gestational age (SGA), 65% were male, and 25% received a tracheostomy. With aggressive cardiopulmonary management including respiratory support optimization, patent ductus arteriosus (PDA) and atrial septal defect (ASD) closure (40% PDA, 5% ASD, 3% both), and limited use of pulmonary vasodilators (8%), all infants demonstrated resolution of PH during the follow-up period, including three (5%) who later died from non-BPD-PH morbidities. Neither SGA status nor the timing of PH diagnosis (<36 vs. ≥36 weeks PMA) impacted the time to BPD-PH resolution in our cohort [median 72 days (IQR 30.5–166.5)].ConclusionOur multidisciplinary, systematic approach to BPD-PH management was associated with complete resolution of PH with lower mortality despite less sildenafil use than reported in comparable cohorts. Unique features of our approach included aggressive PDA and ASD device closure and rare initiation of sildenafil only after lack of BPD-PH improvement with respiratory support optimization and diagnostic confirmation by cardiac catheterization

    An Overview of Marine Biodiversity in United States Waters

    Get PDF
    Marine biodiversity of the United States (U.S.) is extensively documented, but data assembled by the United States National Committee for the Census of Marine Life demonstrate that even the most complete taxonomic inventories are based on records scattered in space and time. The best-known taxa are those of commercial importance. Body size is directly correlated with knowledge of a species, and knowledge also diminishes with distance from shore and depth. Measures of biodiversity other than species diversity, such as ecosystem and genetic diversity, are poorly documented. Threats to marine biodiversity in the U.S. are the same as those for most of the world: overexploitation of living resources; reduced water quality; coastal development; shipping; invasive species; rising temperature and concentrations of carbon dioxide in the surface ocean, and other changes that may be consequences of global change, including shifting currents; increased number and size of hypoxic or anoxic areas; and increased number and duration of harmful algal blooms. More information must be obtained through field and laboratory research and monitoring that involve innovative sampling techniques (such as genetics and acoustics), but data that already exist must be made accessible. And all data must have a temporal component so trends can be identified. As data are compiled, techniques must be developed to make certain that scales are compatible, to combine and reconcile data collected for various purposes with disparate gear, and to automate taxonomic changes. Information on biotic and abiotic elements of the environment must be interactively linked. Impediments to assembling existing data and collecting new data on marine biodiversity include logistical problems as well as shortages in finances and taxonomic expertise

    Especiação e seus mecanismos: histórico conceitual e avanços recentes

    Full text link

    The National Early Warning Score and its subcomponents recorded within ±24 hours of emergency medical admission are poor predictors of hospital-acquired acute kidney injury

    Get PDF
    YesBackground: Hospital-acquired Acute Kidney Injury (H-AKI) is a common cause of avoidable morbidity and mortality. Aim: To determine if the patients’ vital signs data as defined by a National Early Warning Score (NEWS), can predict H-AKI following emergency admission to hospital. Methods: Analyses of emergency admissions to York hospital over 24-months with NEWS data. We report the area under the curve (AUC) for logistic regression models that used the index NEWS (model A0), plus age and sex (A1), plus subcomponents of NEWS (A2) and two-way interactions (A3). Likewise for maximum NEWS (models B0,B1,B2,B3). Results: 4.05% (1361/33608) of emergency admissions had H-AKI. Models using the index NEWS had the lower AUCs (0.59 to 0.68) than models using the maximum NEWS AUCs (0.75 to 0.77). The maximum NEWS model (B3) was more sensitivity than the index NEWS model (A0) (67.60% vs 19.84%) but identified twice as many cases as being at risk of H-AKI (9581 vs 4099) at a NEWS of 5. Conclusions: The index NEWS is a poor predictor of H-AKI. The maximum NEWS is a better predictor but seems unfeasible because it is only knowable in retrospect and is associated with a substantial increase in workload albeit with improved sensitivity.The Health Foundatio

    What’s wrong with evolutionary biology?

    Get PDF
    There have been periodic claims that evolutionary biology needs urgent reform, and this article tries to account for the volume and persistence of this discontent. It is argued that a few inescapable properties of the field make it prone to criticisms of predictable kinds, whether or not the criticisms have any merit. For example, the variety of living things and the complexity of evolution make it easy to generate data that seem revolutionary (e.g. exceptions to well-established generalizations, or neglected factors in evolution), and lead to disappointment with existing explanatory frameworks (with their high levels of abstraction, and limited predictive power). It is then argued that special discontent stems from misunderstandings and dislike of one well-known but atypical research programme: the study of adaptive function, in the tradition of behavioural ecology. To achieve its goals, this research needs distinct tools, often including imaginary agency, and a partial description of the evolutionary process. This invites mistaken charges of narrowness and oversimplification (which come, not least, from researchers in other subfields), and these chime with anxieties about human agency and overall purpose. The article ends by discussing several ways in which calls to reform evolutionary biology actively hinder progress in the field
    • …
    corecore