2,245 research outputs found

    A MATHEMATICAL PROGRAMMING MODEL FOR VEGETABLE ROTATIONS

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    Rotations have historically been used to alleviate pest problems in crop production. This paper considers methods of modeling rotations in linear programming models for Southeastern vegetable production. In such models, entering each possible crop rotation as a separate activity can be burdensome because of the large numbers of possible rotational alternatives. Conventional methodology for double crop rotations reduces the number of activities but must be adapted to accommodate triple crop rotational requirements in vegetable production. This paper demonstrates these methods both for a simple example and an empirical problem with numerous rotation alternatives. While the methods presented in this paper may have computational disadvantages compared to entering each rotation as a separate activity, they do have advantages in model design and data management.Crop Production/Industries,

    The Diagnostic Potential of Transition Region Lines under-going Transient Ionization in Dynamic Events

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    We discuss the diagnostic potential of high cadence ultraviolet spectral data when transient ionization is considered. For this we use high cadence UV spectra taken during the impulsive phase of a solar flares (observed with instruments on-board the Solar Maximum Mission) which showed excellent correspondence with hard X-ray pulses. The ionization fraction of the transition region ion O V and in particular the contribution function for the O V 1371A line are computed within the Atomic Data and Analysis Structure, which is a collection of fundamental and derived atomic data and codes which manipulate them. Due to transient ionization, the O V 1371A line is enhanced in the first fraction of a second with the peak in the line contribution function occurring initially at a higher electron temperature than in ionization equilibrium. The rise time and enhancement factor depend mostly on the electron density. The fractional increase in the O V 1371A emissivity due to transient ionization can reach a factor of 2--4 and can explain the fast response in the line flux of transition regions ions during the impulsive phase of flares solely as a result of transient ionization. This technique can be used to diagnostic the electron temperature and density of solar flares observed with the forth-coming Interface Region Imaging Spectrograph.Comment: 18 pages, 6 figure

    Eradication of hepatitis C infection: the importance of targeting people who inject drugs

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    Hepatitis C virus (HCV) affects ~170 million people worldwide and causes significant morbidity and mortality.1 In high-income countries, people who inject drugs (PWID) are at greatest risk of HCV infection.2 Until recently HCV eradication seemed unlikely, but recent advances in HCV treatment and improved understanding of the effectiveness of harm-reduction intervention effectiveness give reason for optimism. Current HCV treatments can cure ~75% of patients and new drugs will further improve effectiveness (over 90% cure) and improve tolerability.3 If HCV treatment can be delivered effectively to those at highest risk of onward transmission, significant reductions in future HCV cases are possible. The feasibility of disease eradication must be assessed on both scientific criteria (e.g., epidemiological susceptibility, effective and practical intervention available, and demonstrated feasibility of elimination) and political criteria (e.g., burden of disease, cost of intervention).4 With effective, curative treatment now available, HCV meets these criteria

    Theory of impedance networks: The two-point impedance and LC resonances

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    We present a formulation of the determination of the impedance between any two nodes in an impedance network. An impedance network is described by its Laplacian matrix L which has generally complex matrix elements. We show that by solving the equation L u_a = lambda_a u_a^* with orthonormal vectors u_a, the effective impedance between nodes p and q of the network is Z = Sum_a [u_{a,p} - u_{a,q}]^2/lambda_a where the summation is over all lambda_a not identically equal to zero and u_{a,p} is the p-th component of u_a. For networks consisting of inductances (L) and capacitances (C), the formulation leads to the occurrence of resonances at frequencies associated with the vanishing of lambda_a. This curious result suggests the possibility of practical applications to resonant circuits. Our formulation is illustrated by explicit examples.Comment: 21 pages, 3 figures; v4: typesetting corrected; v5: Eq. (63) correcte

    Coronal hole boundaries at small scales: III. EIS and SUMER views

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    We report on the plasma properties of small-scale transient events identified in the quiet Sun, coronal holes and their boundaries. We use spectroscopic co-observations from SUMER/SoHO and EIS/Hinode combined with high cadence imaging data from XRT/Hinode. We measure Doppler shifts using single and multiple Gauss fits of transition region and coronal lines as well as electron densities and temperatures. We combine co-temporal imaging and spectroscopy to separate brightening expansions from plasma flows. The transient brightening events in coronal holes and their boundaries were found to be very dynamical producing high density outflows at large speeds. Most of these events represent X-ray jets from pre-existing or newly emerging coronal bright points at X-ray temperatures. The average electron density of the jets is logNe ~ 8.76 cm^-3 while in the flaring site it is logNe ~ 9.51 cm^-3. The jet temperatures reach a maximum of 2.5 MK but in the majority of the cases the temperatures do not exceed 1.6 MK. The footpoints of jets have temperatures of a maximum of 2.5 MK though in a single event scanned a minute after the flaring the measured temperature was 12 MK. The jets are produced by multiple microflaring in the transition region and corona. Chromospheric emission was only detected in their footpoints and was only associated with downflows. The Doppler shift measurements in the quiet Sun transient brightenings confirmed that these events do not produce jet-like phenomena. The plasma flows in these phenomena remain trapped in closed loops.Comment: 16 pages, accepted for publication in A&

    Stretching of polymers in a random three-dimensional flow

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    Behavior of a dilute polymer solution in a random three-dimensional flow with an average shear is studied experimentally. Polymer contribution to the shear stress is found to be more than two orders of magnitude higher than in a laminar shear flow. The results indicate that the polymer molecules get strongly stretched by the random motion of the fluid.Comment: 4 pages, 3 figure

    Improved Constraints on the Preferential Heating and Acceleration of Oxygen Ions in the Extended Solar Corona

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    We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum are known to exhibit broad line widths and unusual intensity ratios of the O VI 1032, 1037 emission line doublet. The traditional interpretation of these features has been that oxygen ions have a strong temperature anisotropy, with the temperature perpendicular to the magnetic field being much larger than the temperature parallel to the field. However, recent work by Raouafi and Solanki suggested that it may be possible to model the observations using an isotropic velocity distribution. In this paper we analyze an expanded data set to show that the original interpretation of an anisotropic distribution is the only one that is fully consistent with the observations. It is necessary to search the full range of ion plasma parameters to determine the values with the highest probability of agreement with the UVCS data. The derived ion outflow speeds and perpendicular kinetic temperatures are consistent with earlier results, and there continues to be strong evidence for preferential ion heating and acceleration with respect to hydrogen. At heliocentric heights above 2.1 solar radii, every UVCS data point is more consistent with an anisotropic distribution than with an isotropic distribution. At heights above 3 solar radii, the exact probability of isotropy depends on the electron density chosen to simulate the line-of-sight distribution of O VI emissivity. (abridged abstract)Comment: 19 pages (emulateapj style), 13 figures, ApJ, in press (v. 679; May 20, 2008

    Bcl3 prevents acute inflammatory lung injury in mice by restraining emergency granulopoiesis

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    Granulocytes are pivotal regulators of tissue injury. However, the transcriptional mechanisms that regulate granulopoiesis under inflammatory conditions are poorly understood. Here we show that the transcriptional coregulator B cell leukemia/lymphoma 3 (Bcl3) limits granulopoiesis under emergency (i.e., inflammatory) conditions, but not homeostatic conditions. Treatment of mouse myeloid progenitors with G-CSF — serum concentrations of which rise under inflammatory conditions — rapidly increased Bcl3 transcript accumulation in a STAT3-dependent manner. Bcl3-deficient myeloid progenitors demonstrated an enhanced capacity to proliferate and differentiate into granulocytes following G-CSF stimulation, whereas the accumulation of Bcl3 protein attenuated granulopoiesis in an NF-κB p50–dependent manner. In a clinically relevant model of transplant-mediated lung ischemia reperfusion injury, expression of Bcl3 in recipients inhibited emergency granulopoiesis and limited acute graft damage. These data demonstrate a critical role for Bcl3 in regulating emergency granulopoiesis and suggest that targeting the differentiation of myeloid progenitors may be a therapeutic strategy for preventing inflammatory lung injury

    Telehealth and Mobile Health Applied To IntegratedBehavioral Care: OpportunitiesFor Progress In New Hampshire

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    This paper is an accompanying document to a webinar delivered on May 16, 2017, for the New Hampshire Citizens Health Initiative (Initiative). As integrated behavioral health efforts in New Hampshire gain traction, clinicians, administrators, payers, and policy makers are looking for additional efficiencies in delivering high quality healthcare. Telehealth and mobile health (mHealth) have the opportunity to help achieve this while delivering a robust, empowered patient experience. The promise of video-based technology was first made in 1964 as Bell Telephone shared its Picturephone® with the world. This was the first device with audio and video delivered in an integrated technology platform. Fast-forward to today with Skype, FaceTime, and webinar tools being ubiquitous in our personal and business lives, but often slow to be adopted in the delivery of medicine. Combining technology-savvy consumers with New Hampshire’s high rate of electronic health record (EHR) technology adoption, a fairly robust telecommunications infrastructure, and a predominately rural setting, there is strong foundation for telehealth and mHealth expansion in New Hampshire’s integrated health continuum

    Integrating Behavioral Health & Primary Care in New Hampshire: A Path Forward to Sustainable Practice & Payment Transformation

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    New Hampshire residents face challenges with behavioral and physical health conditions and the interplay between them. National studies show the costs and the burden of illness from behavioral health conditions and co-occurring chronic health conditions that are not adequately treated in either primary care or behavioral health settings. Bringing primary health and behavioral health care together in integrated care settings can improve outcomes for both behavioral and physical health conditions. Primary care integrated behavioral health works in conjunction with specialty behavioral health providers, expanding capacity, improving access, and jointly managing the care of patients with higher levels of acuity In its work to improve the health of NH residents and create effective and cost-effective systems of care, the NH Citizens Health Initiative (Initiative) created the NH Behavioral Health Integration Learning Collaborative (BHI Learning Collaborative) in November of 2015, as a project of its Accountable Care Learning Network (NHACLN). Bringing together more than 60 organizations, including providers of all types and sizes, all of the state’s community mental health centers, all of the major private and public insurers, and government and other stakeholders, the BHI Learning Collaborative built on earlier work of a NHACLN Workgroup focused on improving care for depression and co-occurring chronic illness. The BHI Learning Collaborative design is based on the core NHACLN philosophy of “shared data and shared learning” and the importance of transparency and open conversation across all stakeholder groups. The first year of the BHI Learning Collaborative programming included shared learning on evidence-based practice for integrated behavioral health in primary care, shared data from the NH Comprehensive Healthcare Information System (NHCHIS), and work to develop sustainable payment models to replace inadequate Fee-for-Service (FFS) revenues. Provider members joined either a Project Implementation Track working on quality improvement projects to improve their levels of integration or a Listen and Learn Track for those just learning about Behavioral Health Integration (BHI). Providers in the Project Implementation Track completed a self-assessment of levels of BHI in their practice settings and committed to submit EHR-based clinical process and outcomes data to track performance on specified measures. All providers received access to unblinded NHACLN Primary Care and Behavioral Health attributed claims data from the NHCHIS for provider organizations in the NH BHI Learning Collaborative. Following up on prior work focused on developing a sustainable model for integrating care for depression and co-occurring chronic illness in primary care settings, the BHI Learning Collaborative engaged consulting experts and participants in understanding challenges in Health Information Technology and Exchange (HIT/HIE), privacy and confidentiality, and workforce adequacy. The BHI Learning Collaborative identified a sustainable payment model for integrated care of depression in primary care. In the process of vetting the payment model, the BHI Learning Collaborative also identified and explored challenges in payment for Substance Use Disorder Screening, Brief Intervention and Referral to Treatment (SBIRT). New Hampshire’s residents will benefit from a health care system where primary care and behavioral health are integrated to support the care of the whole person. New Hampshire’s current opiate epidemic accentuates the need for better screening for behavioral health issues, prevention, and treatment referral integrated into primary care. New Hampshire providers and payers are poised to move towards greater integration of behavioral health and primary care and the Initiative looks forward to continuing to support progress in supporting a path to sustainable integrated behavioral and primary care
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