603 research outputs found

    Test of the Skyrme Effective Field Theory Using Quenched Lattice QCD

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    The Skyrme effective field theory is tested by evaluating nucleon ground state matrix elements of the correlation functions for two flavor density operators and two pseudoscalar density operators in the Skyrme model and comparing them with results in quenched lattice QCD. The possiblility of using quenched lattice QCD to study higher-order terms in effective field theory is also discussed.Comment: 20 pages in TeX, 6 figures added using "figures", MIT-CTP-200

    Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

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    Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs. Thus, individuals with D4 receptor polymorphisms might show enhanced reinforcing responses to MP and AMPH and attenuated locomotor response to AMPH.Fil: Thanos, P. K.. NIAAA Intramural Program; Estados Unidos. Brookhaven National Laboratory; Estados Unidos. Universidad de Buenos Aires; ArgentinaFil: Bermeo, C.. Brookhaven National Laboratory; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Suchland, K. L.. Oregon Health & Science University; Estados UnidosFil: Wang, G. J.. Brookhaven National Laboratory; Estados UnidosFil: Grandy, David K.. Oregon Health & Science University; Estados UnidosFil: Volkow, N. D.. NIAAA Intramural Program; Estados Unido

    Lattice Calculation of Point-to-Point Hadron Current Correlation

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    Point-to-point correlation functions of hadron currents in the QCD vacuum are calculated on a lattice and analyzed using dispersion relations, providing physical information down to small spatial separations. Qualitative agreement with phenomenological results is obtained in channels for which experimental data are available, and these correlation functions are shown to be useful in exploring approximations based on sum rules and interacting instantons.Comment: 11 page

    Correlation Functions of Hadron Currents in the QCD Vacuum Calculated in Lattice QCD

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    Point-to-point vacuum correlation functions for spatially separated hadron currents are calculated in quenched lattice QCD on a 163×2416^3\times 24 lattice with 6/g2=5.76/g^2=5.7. The lattice data are analyzed in terms of dispersion relations, which enable us to extract physical information from small distances where asymptotic freedom is apparent to large distances where the hadronic resonances dominate. In the pseudoscalar, vector, and axial vector channels where experimental data or phenomenological information are available, semi-quantitative agreement is obtained. In the nucleon and delta channels, where no experimental data exist, our lattice data complement experiments. Comparison with approximations based on sum rules and interacting instantons are made, and technical details of the lattice calculation are described.Comment: 31 pages in REVTeX (with 10 figures to be added using figures command), MIT CTP #214

    Trait-based assembly of arbuscular mycorrhizal fungal communities determines soil carbon formation and retention

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    Fungi are crucial for soil organic carbon (SOC) formation, especially for the more persistent mineral-associated organic C (MAOC) pool. Yet, evidence for this often overlooks arbuscular mycorrhizal fungi (AMF) communities and how their composition and traits impact SOC accumulation. We grew sudangrass with AMF communities representing different traits conserved at the family level: competitors, from the Gigasporaceae family; ruderals, from the Glomeraceae family; or both families combined. We labeled sudangrass with 13C-CO2 to assess AMF contributions to SOC, impacts on SOC priming, and fungal biomass persistence in MAOC. Single-family AMF communities decreased total SOC by 13.8%, likely due to fungal priming. Despite net SOC losses, all AMF communities contributed fungal C to soil but only the Glomeraceae community initially contributed to MAOC. After a month of decomposition, both the Glomeraceae and mixed-family communities contributed to MAOC formation. Plant phosphorus uptake, but not hyphal chemistry, was positively related to AMF soil C and MAOC accumulation. Arbuscular mycorrhizal fungi contribution to MAOC is dependent on the specific traits of the AMF community and related to phosphorus uptake. These findings provide insight into how variations in AMF community composition and traits, and thus processes like environmental filtering of AMF, may impact SOC accumulation

    Retaining eucalyptus harvest residues promotes different pathways for particulate and mineral-associated organic matter

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    Eucalyptus plantations have replaced other (agro)ecosystems over 5.6 Mha in Brazil. While these plantations rapidly accumulate carbon (C) in their biomass, the C storage in living forest biomass is transient, and thus, longer-term sustainability relies on sustaining soil organic matter (SOM) stocks. A significant amount of harvest residues (HR) is generated every rotation and can yield SOM if retained in the field. Yet, there is little information on how managing eucalyptus HR changes SOM dynamics. We used isotopic and molecular approaches in a 3-yr field decomposition experiment where a native grassland has been replaced by eucalyptus plantations to assess how HR management practices influence content and chemistry of two distinct SOM fractions [particulate (POM) and mineral-associated organic matter (MAOM)] at two soil depths (0–1 and 1–5 cm). The management practices investigated were HR removal (−R), only bark removal (−B), and retention of all HR (including bark, +B), combined with two levels of nitrogen (N) fertilization [0 (−N) and 200 (+N) kg/ha]. N fertilization inhibited HR decomposition (P = 0.0409), while bark retention had little effect (P = 0.1164). Retaining HR, especially with bark, increased POM-C and MAOM-C content (2.1- and 1.2-fold, respectively), decreased POM-δ13C (1.2-fold), and increased inorganic N retention (1.7-fold) compared with plots where HR had been removed. Inorganic N applications, however, diminished the positive impacts of bark retention. Although the influence of HR management was most pronounced in POM, retaining HR reduced potential soil C mineralization by up to 20%. POM and MAOM chemistry shifted over time and revealed distinct influence of HR on the formation of these fractions. We demonstrate that HR management alters SOM dynamics and that retaining HR, particularly including bark, enhances SOM retention. With continuing conversion of native grassland ecosystems to eucalyptus, long-term sustainability will require careful HR and fertilizer management to balance total biomass harvest with sustaining belowground SOM concentrations

    The Three Neurogenetic Phases of Human Consciousness.

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    ABSTRACT This paper is an organization and conceptualization of a genetic account of human consciousness and to establish an initial list of the neurogenetic correlates of consciousness (NgCC). This will be accomplished by establishing networks of genes that are involved in the multiple facets of the process of human consciousness. The methodology utilized in this work is the evaluation of a small number of genes that have been researched experimentally in order to understand their role in brain development and function. The results demonstrate that most neurogenetic genes can be categorized into three phases: the emergence of neuron-based consciousness, the continuum of neuron-based consciousness, and the neurodegeneration of consciousness. This work also revealed that some genes have a function in more than one of the neurogenetic phases. As of now a starting point has been established in terms of identifying some NgCC but there is room for expansion as there are likely to be hundreds of more genes that have yet to be identified or the function pertaining to human consciousness has not yet been fully understood

    PENGENALAN KONSEP AGROPOLITAN DI KECAMATAN JUMAPOLO KABUPATEN KARANGANYAR

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    Agropolitan berarti kota yang fokus pada pertanian. Salah satu kawasan yang memiliki potensi pertanian sangat besar adalah Kecamatan Jumapolo yang terletak di Pulau Jawa bagian tengah. Kecamatan ini terletak di daerah subur sehingga sangat cocok untuk budidaya padi. Pemerintah harus memberikan dukungan teknis untuk membantu penduduk desa mempelajari cara terbaik menggunakan sumber daya yang tersedia dan meningkatkan teknik pertanian mereka. Salah satunya dalam penataan peruntukan ruang pertanian agar ke depan dapat menjamin keberlanjutan aktivitas pertanian dan sebagai stategi dalam beradaptasi dalam era globalisasi saat ini dan masa yang akan datang. Penerapan konsep agriculture adalah sebagai suatu konsep permukiman yang melakukan kegiatan yang memanfaatkan hasil pertanian sebagai bahan baku, merancang, dan menyediakan peralatan serta jasa untuk kegiatan tersebut. Pemilihan konsep ini didasari dari karakteristik wilayah deliniasi yang merupakan pertanian. Dengan adanya konsep yang direncanakan di Kecamatan Jumapolo ini, diharapkan dapat membantu dalam mengatasi permasalahan yang ada dan memanfaat potensi yang dimiliki tanpa mengubah karakteristik yang dimiliki wilayah tersebut. Metode yang digunakan adalah metode deskriptif kualitatif. Metode deskripstif kualitatif ini dilakukan apabila peneliti hendak mengeksplor fenomena pada suatu objek yang tidak dapat dikuantifikasikan yang bersifat deskriptif atau naratif. Kata kunci : agropolitan, agriculture, pertania

    Use of Wearable Activity-Monitoring Technologies to Promote Physical Activity in Cancer Survivors: Challenges and Opportunities for Improved Cancer Care

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    The aim of this review was to explore the acceptability, opportunities, and challenges associated with wearable activity-monitoring technology to increase physical activity (PA) behavior in cancer survivors. A search of Medline, Embase, CINAHL, and SportDiscus was conducted from 1 January 2011 through 3 October 2022. The search was limited to English language, and peer-reviewed original research. Studies were included if they reported the use of an activity monitor in adults (+18 years) with a history of cancer with the intent to motivate PA behavior. Our search identified 1832 published articles, of which 28 met inclusion/exclusion criteria. Eighteen of these studies included post-treatment cancer survivors, eight were on active cancer treatment, and two were long-term cancer survivor studies. ActiGraph accelerometers were the primary technology used to monitor PA behaviors, with Fitbit as the most commonly utilized self-monitoring wearable technology. Overall, wearable activity monitors were found to be an acceptable and useful tool in improving self-awareness, motivating behavioral change, and increasing PA levels. Self-monitoring wearable activity devices have a positive impact on short-term PA behaviors in cancer survivors, but the increase in PA gradually attenuated through the maintenance phase. Further study is needed to evaluate and increase the sustainability of the use of wearable technologies to support PA in cancer survivors
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