476 research outputs found

    A Simple Method for Estimating Alfalfa Fiber Content in the Field

    Get PDF
    Predictive equations for alfalfa (Medicago sativa L.) quality (PEAQ) based on length of the longest stem and maturity stage of the most mature stem in a sample were developed and validated for estimating neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations in alfalfa. The objective of this research was to validate PEAQ with a simplified maturity scale when estimating fiber content. Alfalfa samples varying in height and maturity were collected throughout the growing season from fields across six states in USA. Observed NDF and ADF values (determined via wet chemistry) were regressed on estimated values. The estimated values were calculated with PEAQ using the Kalu and Fick maturity scale (stages 2 to 6) and using a modified 3-stage scale consisting of vegetative stage (Kalu and Fick stage 2.0), bud stage (stage 3.5, i.e. averaged Kalu and Fick bud stages 3 and 4), and flower stage (stage 5.5, i.e. averaged Kalu and Fick flower stages 5 and 6). Regression equations for NDF and ADF were slightly biased (b 1.0 and/or y-intercept 0) for two of the three datasets regardless of the staging scale used. Prediction errors were similar regardless of the staging scale, ranging from 16.8 to 25.4 g kg-1 for NDF and 14.3 to 19.3 g kg-1 for ADF. We conclude that the 3-stage maturity scale can be used effectively in these equations for estimating alfalfa fiber content based on a combination of stem length and maturity

    Phenotype bias determines how natural RNA structures occupy the morphospace of all possible shapes

    Get PDF
    The relative prominence of developmental bias versus natural selection is a long standing controversy in evolutionary biology. Here we demonstrate quantitatively that developmental bias is the primary explanation for the occupation of the morphospace of RNA secondary structure (SS) shapes. By using the RNAshapes method to define coarse-grained SS classes, we can measure the frequencies that non-coding RNA SS shapes appear in nature. Our main findings are firstly that only the most frequent structures appear in nature; the vast majority of possible structures in the morphospace have not yet been explored. Secondly, and perhaps more surprisingly, these frequencies are accurately predicted by the likelihood that structures appear upon uniform random sampling of sequences. The ultimate cause of these patterns is not natural selection, but rather strong phenotype bias in the RNA genotype-phenotype (GP) map, a type of developmental bias which tightly constrains evolutionary dynamics to only act within a reduced subset of structures that are easy to “find”. Preprint on: https://www.biorxiv.org/content/10.1101/2020.12.03.410605v

    Qudits of composite dimension, mutually unbiased bases and projective ring geometry

    Full text link
    The d2d^2 Pauli operators attached to a composite qudit in dimension dd may be mapped to the vectors of the symplectic module Zd2\mathcal{Z}_d^{2} (Zd\mathcal{Z}_d the modular ring). As a result, perpendicular vectors correspond to commuting operators, a free cyclic submodule to a maximal commuting set, and disjoint such sets to mutually unbiased bases. For dimensions d=6, 10, 15, 12d=6,~10,~15,~12, and 18, the fine structure and the incidence between maximal commuting sets is found to reproduce the projective line over the rings Z6\mathcal{Z}_{6}, Z10\mathcal{Z}_{10}, Z15\mathcal{Z}_{15}, Z6×F4\mathcal{Z}_6 \times \mathbf{F}_4 and Z6×Z3\mathcal{Z}_6 \times \mathcal{Z}_3, respectively.Comment: 10 pages (Fast Track communication). Journal of Physics A Mathematical and Theoretical (2008) accepte

    New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"

    Full text link
    Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green at the single wavelength of 532 nm. No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit to be less than 3.51083.5\cdot 10^{-8} GeV1^{-1} and 3.21083.2\cdot 10^{-8} GeV1^{-1}, respectively, at 95% Confidence Level.Comment: 6 pages, 6 figure

    Production Systems to Integrate Livestock Grazing and Grain Production in Southern Brazil and Midwestern USA

    Get PDF
    Agriculture in the USA and Brazil has undergone similar and dramatic changes in the past 20 years. In both countries, production systems have become increasingly specialized. Large farms are characterized by single enterprises, simple crop rotations, and livestock production is segregated from grain production. The lack of diversification and high production costs expose producers to risk from economic swings of single enterprises and greater reliance on pesticides and synthetic fertilizers to maintain profitability, along with greater risk of soil erosion from continuous row crop production. Scientists in southern Brazil and Ohio are collaborating to develop no-tillage systems that integrate livestock grazing with cash grain production. The goal is diversified production systems that are profitable as well as biologically and environmentally sound

    First results from the OSQAR photon regeneration experiment: No light shining through a wall

    Get PDF
    A new method to amplify the photon-axion conversions in magnetic field is proposed using a buffer gas at a specific pressure. As a first result, new bounds for mass and coupling constant for purely laboratory experiments aiming to detect any hypothetical scalars and pseudo-scalars which can couple to photons were obtained at 95% confidence level, excluding the PVLAS result newly disclaimed.Comment: 4 pages, 5 figure

    Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives

    Get PDF
    Recent theoretical and experimental studies highlight the possibility of new fundamental particle physics beyond the Standard Model that can be probed by sub-eV energy experiments. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" (LSW) from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or axion-like particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. No excess of events has been detected over the background. The di-photon couplings of possible new light scalar and pseudo-scalar particles can be constrained in the massless limit to be less than 8.0×1088.0\times10^{-8} GeV1^{-1}. These results are very close to the most stringent laboratory constraints obtained for the coupling of ALPs to two photons. Plans for further improving the sensitivity of the OSQAR experiment are presented.Comment: 7 pages, 7 figure

    Weak mutually unbiased bases

    Full text link
    Quantum systems with variables in Z(d){\mathbb Z}(d) are considered. The properties of lines in the Z(d)×Z(d){\mathbb Z}(d)\times {\mathbb Z}(d) phase space of these systems, are studied. Weak mutually unbiased bases in these systems are defined as bases for which the overlap of any two vectors in two different bases, is equal to d1/2d^{-1/2} or alternatively to one of the di1/2,0d_i^{-1/2},0 (where did_i is a divisor of dd apart from d,1d,1). They are designed for the geometry of the Z(d)×Z(d){\mathbb Z}(d)\times {\mathbb Z}(d) phase space, in the sense that there is a duality between the weak mutually unbiased bases and the maximal lines through the origin. In the special case of prime dd, there are no divisors of dd apart from 1,d1,d and the weak mutually unbiased bases are mutually unbiased bases

    Comparable, but distinct: Perceptions of primary care provided by physicians and nurse practitioners in full and restricted practice authority states

    Full text link
    AimsTo understand patients- and providers- perceptions of primary care delivered by nurse practitioners (NPs) in the Veterans Affairs Healthcare System.DesignQualitative exploratory study (in convergent mixed- methods design).MethodsSemi- structured interviews in 2016 with primary care providers and patients from facilities in states with full and restricted practice authority for NPs. Patient sample based on reassignment to: (a) a NP; or (b) a different physician following an established physician relationship. Data were analysed using content analysis.ResultsWe interviewed 28 patients, 17 physicians and 14 NPs. We found: (a) NPs provided more holistic care than physicians; (b) patients were satisfied with NPs; and (c) providers- professional experience outweighed provider type.ConclusionsPatients- preferences for NPs (compared with prior physicians) contributed to perceptions of patient centredness. Similarities in providers- perceptions suggest NPs and physicians are both viable providers for primary care.ImpactNurse Practitioners (NPs): practice authorityVeterans Affairs Health care: nurse practitioners will continue to be a viable resource for primary care deliveryUnited States Health care: challenges notions patients may not be satisfied with care provided by NPs and supports expanding their use to provide much- needed access to primary care services; expanding Full Practice Authority would allow states to provide acceptable primary care without diminishing patient or provider experiencesæ è¦ ç ®æ  äº è§£æ £è å å »ç æ ºæ 对é ä¼ å äººå »ç ä¿ å ¥ç³»ç» ä¸­æ ¤ç å¸ æ ä¾ å çº§æ ¤ç ç ç æ³ ã è®¾è®¡æ ¢ç´¢æ §ç å® æ §ç  ç©¶(æ ¶æ æ··å æ ¹æ³ è®¾è®¡)ã æ ¹æ³ 2016å¹´è¿ è¡ ç å ç» æ å è®¿è° ,é è®¿äº å· å æ ¥æ æ ¤ç å¸ ç å ¨ç§ å é å ¨ç§ æ §ä¸ æ ºæ ç å çº§æ ¤ç æ ä¾ è å æ £è ã é æ °å é æ £è æ ·æ ¬:(a) ä¸ å æ ¤ç å¸ ;æ (b)ç¡®ç« å »ç å ³ç³»ç å ¦ä¸ å å »ç ã é ç ¨å 容å æ æ³ å¯¹æ °æ ®è¿ è¡ å æ ã ç» æ æ 们é è®¿äº 28å æ £è ,17å å »ç å 14å æ ¤ç å¸ ã æ 们å ç °:(a)æ ¤ç å¸ æ¯ å »ç æ ä¾ ç æ ¤ç æ ´å ¨é ¢;(b)æ £è å¯¹æ ¤ç å¸ æ å °æ»¡æ ;(c)å »ç æ ºæ ç ä¸ ä¸ ç» éª ç æ é æ¯ å »ç æ ºæ ç±»å ç æ é æ ´å¤§ã ç» è®ºæ £è å¯¹æ ¤ç å¸ ç å 好(ä¸ ä»¥å ç å »ç ç ¸æ¯ )æ å ©äº å»ºç« ä»¥æ £è ä¸ºä¸­å¿ ç è®¤ç ¥ã æ ä¾ è ç è§ å¿µç±»ä¼¼,表æ æ ¤ç å¸ å å »ç é ½æ ¯å ¯è¡ ç å çº§æ ¤ç æ ä¾ è ã å½±å - ¢æ ¤ç å¸ :æ §ä¸ æ ºæ - ¢é ä¼ å äººå »ç ä¿ å ¥ç³»ç» :æ ¤ç å¸ å° ç»§ç»­ä½ ä¸ºæ ä¾ å çº§æ ¤ç æ å ¡ç å ¯ç ¨èµ æº ã - ¢ç¾ å ½å «ç ä¿ å ¥:æ æ è§ å¿µ æ £è å ¯è ½ä¸ æ»¡æ ç ±æ ¤ç å¸ æ ä¾ ç æ ¤ç ,å ¶ä¼ æ ¯æ æ ©å¤§ä½¿ç ¨è å ´,以æ ä¾ æ ¥é ç å çº§ä¿ å ¥æ å ¡;æ ©å¤§å ¨ç§ æ §ä¸ æ ºæ å° ä½¿å å· è ½å¤ æ ä¾ å ¯æ ¥å ç å çº§ä¿ å ¥æ å ¡,è ä¸ ä¼ å å¼±æ £è æ æ ä¾ è ç ä½ éª ãPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163369/2/jan14501.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163369/1/jan14501_am.pd

    Outcomes of primary care delivery by nurse practitioners: Utilization, cost, and quality of care

    Full text link
    ObjectiveTo examine whether nurse practitioner (NP)- assigned patients exhibited differences in utilization, costs, and clinical outcomes compared to medical doctor (MD)- assigned patients.Data SourcesVeterans Affairs (VA) administrative data capturing characteristics, outcomes, and provider assignments of 806 434 VA patients assigned to an MD primary care provider (PCP) who left VA practice between 2010 and 2012.Study DesignWe applied a difference- in- difference approach comparing outcomes between patients reassigned to MD and NP PCPs, respectively. We examined measures of outpatient (primary care, specialty care, and mental health) and inpatient (total and ambulatory care sensitive hospitalizations) utilization, costs (outpatient, inpatient and total), and clinical outcomes (control of hemoglobin A1c, LDL, and blood pressure) in the year following reassignment.Principal FindingsCompared to MD- assigned patients, NP- assigned patients were less likely to use primary care and specialty care services and incurred fewer total and ambulatory care sensitive hospitalizations. Differences in costs, clinical outcomes, and receipt of diagnostic tests between groups were not statistically significant.ConclusionsPatients reassigned to NPs experienced similar outcomes and incurred less utilization at comparable cost relative to MD patients. NPs may offer a cost- effective approach to addressing anticipated shortages of primary care physicians.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154625/1/hesr13246_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154625/2/hesr13246-sup-0001-Authormatrix.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154625/3/hesr13246.pd
    corecore