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KEY POINTS Within skeletal muscle the greatest resistance to oxygen transport is thought to reside across the short distance at the red blood cell-myocyte interface. These structures generate a significant transmural oxygen pressure (PO2 ) gradient in mixed fibre-type muscle. Increasing O2 flux across the capillary wall during exercise depends on: (i) the transmural O2 pressure gradient, which is maintained in mixed-fibre muscle, and/or (ii) elevating diffusing properties between microvascular and interstitial compartments resulting, in part, from microvascular haemodynamics and red blood cell distribution. We evaluated the PO2 within the microvascular and interstitial spaces of muscles spanning the slow- to fast-twitch fibre and high- to low-oxidative capacity spectrums, at rest and during contractions, to assess the magnitude of transcapillary PO2 gradients in rats. Our findings demonstrate that, across the metabolic rest-contraction transition, the transcapillary pressure gradient for O2 flux is: (i) maintained in all muscle types, and (ii) the lowest in contracting highly oxidative fast-twitch muscle. ABSTRACT In mixed fibre-type skeletal muscle transcapillary PO2 gradients (PO2 mv-PO2 is; microvascular and interstitial, respectively) drive O2 flux across the blood-myocyte interface where the greatest resistance to that O2 flux resides. We assessed a broad spectrum of fibre-type and oxidative-capacity rat muscles across the rest-to-contraction (1 Hz, 120 s) transient to test the novel hypotheses that: (i) slow-twitch PO2 is would be greater than fast-twitch, (ii) muscles with greater oxidative capacity have greater PO2 is than glycolytic counterparts, and (iii) whether PO2 mv-PO2 is at rest is maintained during contractions across all muscle types. PO2 mv and PO2 is were determined via phosphorescence quenching in soleus (SOL; 91% type I+IIa fibres and CSa: ∼21 μmol min-1 g-1 ), peroneal (PER; 33% and ∼20 μmol min-1 g-1 ), mixed (MG; 9% and ∼26 μmol min-1 g-1 ) and white gastrocnemius (WG; 0% and ∼8 μmol min-1 g-1 ) across the rest-contraction transient. PO2 mv was higher than PO2 is in each muscle (∼6-13 mmHg; P

Exercise intolerance is a primary symptom of heart failure (HF); however, the specific contribution of central and peripheral factors to this intolerance is not well described. The hyperbolic relationship between exercise intensity and time to exhaustion (speed-duration relationship) defines exercise tolerance but is underused in HF. We tested the hypotheses that critical speed (CS) would be reduced in HF, resting central functional measurements would correlate with CS, and the greatest HF-induced peripheral dysfunction would occur in more oxidative muscle. Multiple treadmill-constant speed runs to exhaustion were used to quantify CS and D′ (distance coverable above CS) in healthy control (Con) and HF rats. Central function was determined via left ventricular (LV) Doppler echocardiography [fractional shortening (FS)] and a micromanometer-tipped catheter [LV end-diastolic pressure (LVEDP)]. Peripheral O2 delivery-to-utilization matching was determined via phosphorescence quenching (interstitial Po2, Po2 is) in the soleus and white gastrocnemius during electrically induced twitch contractions (1 Hz, 8V). CS was lower in HF compared with Con (37 ± 1 vs. 44 ± 1 m/min, P < 0.001), but D′ was not different (77 ± 8 vs. 69 ± 13 m, P = 0.6). HF reduced FS (23 ± 2 vs. 47 ± 2%, P < 0.001) and increased LVEDP (15 ± 1 vs. 7 ± 1 mmHg, P < 0.001). CS was related to FS ( r = 0.72, P = 0.045) and LVEDP ( r = −0.75, P = 0.02) only in HF. HF reduced soleus Po2 is at rest and during contractions (both P < 0.01) but had no effect on white gastrocnemius Po2 is ( P > 0.05). We show in HF rats that decrements in central cardiac function relate directly with impaired exercise tolerance (i.e., CS) and that this compromised exercise tolerance is likely due to reduced perfusive and diffusive O2 delivery to oxidative muscles. NEW & NOTEWORTHY We show that critical speed (CS), which defines the upper boundary of sustainable activity, can be resolved in heart failure (HF) animals and is diminished compared with controls. Central cardiac function is strongly related with CS in the HF animals, but not controls. Skeletal muscle O2 delivery-to-utilization dysfunction is evident in the more oxidative, but not glycolytic, muscles of HF rats and is explained, in part, by reduced nitric oxide bioavailability.

Sex differences in the mechanisms underlying cardiovascular pathophysiology of O2 transport in heart failure (HF) remain to be explored. In HF, nitric oxide (NO) bioavailability is reduced and contributes to deficits in O2 delivery-to-utilization matching. Females may rely more on NO for cardiovascular control and as such experience greater decrements in HF. We tested the hypotheses that moderate HF induced by myocardial infarction would attenuate the skeletal muscle interstitial Po2 response to contractions (Po2is; determined by O2 delivery-to-utilization matching) compared with healthy controls and females would express greater dysfunction than male counterparts. Furthermore, we hypothesized that 5 days of dietary nitrate supplementation (Nitrate; 1 mmol·kg−1·day−1) would raise Po2is in HF rats. Forty-two Sprague-Dawley rats were randomly assigned to healthy, HF, or HF + Nitrate groups (each n = 14; 7 female/7 male). Spinotrapezius Po2is was measured via phosphorescence quenching during electrically induced twitch contractions (180 s; 1 Hz). HF reduced resting Po2is for both sexes compared with healthy controls ( P < 0.01), and females were lower than males (14 ± 1 vs. 17 ± 2 mmHg) ( P < 0.05). In HF both sexes expressed reduced Po2is amplitudes following the onset of muscle contractions compared with healthy controls (female: −41 ± 7%, male: −26 ± 12%) ( P < 0.01). In HF rats, Nitrate elevated resting Po2is to values not different from healthy rats and removed the sex difference. Female HF + Nitrate rats expressed greater resting Po2is and amplitudes compared with female HF ( P < 0.05). In this model of moderate HF, O2 delivery-to-utilization matching in the interstitial space is diminished in a sex-specific manner and dietary nitrate supplementation may serve to offset this reduction in HF rats with greater effects in females. NEW & NOTEWORTHY Interstitial Po2 (Po2is; indicative of O2 delivery-to-utilization matching) determines, in part, O2 flux into skeletal muscle. We show that heart failure (HF) reduces Po2is at rest and during skeletal muscle contractions in rats and this negative effect is amplified for females. However, elevating NO bioavailability with dietary nitrate supplementation increases resting Po2is and alters the dynamic response with greater efficacy in female HF rats, particularly at rest and following the onset of muscle contractions.

Cardiovascular adaptations to exercise, particularly at the individual level, remain poorly understood. Previous group level research suggests the relationship between cardiac output and oxygen consumption ([Formula: see text]-[Formula: see text]) is unaffected by training as submaximal [Formula: see text] is unchanged. We recently identified substantial inter-individual variation in the exercise [Formula: see text]-[Formula: see text] relationship that was correlated to stroke volume (SV) as opposed to arterial oxygen content. Therefore we explored the effects of sprint interval training (SIT) on modulating [Formula: see text]-[Formula: see text] given an individual's specific [Formula: see text]-[Formula: see text] relationship. 22 (21±2 yrs) healthy, recreationally active males participated in a 4-week SIT (8, 20 second sprints; 4x/week, 170% of the work rate at [Formula: see text] peak) study with progressive exercise tests (PET) until exhaustion. Cardiac output ([Formula: see text] L/min; inert gas rebreathe, Finometer Modelflow™), oxygen consumption ([Formula: see text] L/min; breath-by-breath pulmonary gas exchange), quadriceps oxygenation (near infrared spectroscopy) and exercise tolerance (6-20; Borg Scale RPE) were measured throughout PET both before and after training. Data are mean Δ from bsl±SD. Higher [Formula: see text] ([Formula: see text]) and lower [Formula: see text] ([Formula: see text]) responders were identified post hoc (n = 8/group). SIT increased the [Formula: see text]-[Formula: see text] post-training in [Formula: see text] (3.8±0.2 vs. 4.7±0.2; P = 0.02) while [Formula: see text] was unaffected (5.8±0.1 vs. 5.3±0.6; P = 0.5). [Formula: see text] was elevated beyond 80 watts in [Formula: see text] due to a greater increase in SV (all P0.1). In contrast to [Formula: see text], [Formula: see text] responders are capable of improving submaximal [Formula: see text]-[Formula: see text] in response to SIT via increased SV. However, the increased submaximal exercise [Formula: see text] does not benefit exercising muscle oxygenation.

A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the reactions over all the energy regions. A description of the neutrino-nucleon reactions follows and, in particular, a dynamical coupled-channels model for meson productions in and beyond the $\Delta$(1232) region is discussed in detail. We then discuss the neutrino-nucleus reactions, putting emphasis on our theoretical approaches. We start the discussion with electroweak processes in few-nucleon systems studied with the correlated Gaussian method. Then we describe quasi-elastic scattering with nuclear spectral functions, and meson productions with a $\Delta$-hole model. Nuclear modifications of the parton distribution functions determined through a global analysis are also discussed. Finally, we discuss issues to be addressed for future developments., Comment: 68 pages, 33 figures; (v2) reference added, author name in metadata corrected; (v3) Discussion extended in Sec. I and IV, Fig. 10 added to compare with a previous result on two-pion productions, Table I extended to include a comparison with a recent T2K result on coherent pion production

Cerebral blood flow (CBF) and oxygenation (COx) are generally well-preserved in COPD. It is unknown whether prevalent cardiovascular co-morbidities, such as heart failure, may impair CBF and COx responses to exertion. Eighteen males with moderate-to-severe COPD (8 with and 10 without overlapping heart failure) underwent a progressive exercise test with pre-frontal CBF and COx measurements (indocyanine green and near-infrared spectroscopy). Mean arterial pressure and cardiac output were lower from rest to exercise in overlap. Only COPD patients demonstrated an increase in arterialized PCO2 towards the end of progressive exercise. CBF index was consistently higher and increased further by similar to 40% during exercise in COPD whereas a similar to 10% reduction was observed in overlap. COx was lower in overlap despite preserved arterial oxygenation. In conclusion, heart failure introduces pronounced negative effects on CBF and COx in COPD which may be associated with clinically relevant outcomes, including dyspnea, exercise intolerance, cerebrovascular disease and cognitive impairment. (C) 2015 Elsevier B.V. All rights reserved. Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil Respiratory Investigation Unit & Laboratory of Clinical Exercise Physiology, Queen’s University & Kingston General Hospital, Kingston, ON, Canada Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respirology, Federal University of Sao Paulo, Sao Paulo, Brazil Web of Science

Impairment in oxygen (O2) delivery to the central nervous system ("brain") and skeletal locomotor muscle during exercise has been associated with central and peripheral neuromuscular fatigue in healthy humans. From a clinical perspective, impaired tissue O2 transport is a key pathophysiological mechanism shared by cardiopulmonary diseases, such as chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). In addition to arterial hypoxemic conditions in COPD, there is growing evidence that cerebral and muscle blood flow and oxygenation can be reduced during exercise in both isolated COPD and CHF. Compromised cardiac output due to impaired cardiopulmonary function/interactions and blood flow redistribution to the overloaded respiratory muscles (i.e., ↑work of breathing) may underpin these abnormalities. Unfortunately, COPD and CHF coexist in almost a third of elderly patients making these mechanisms potentially more relevant to exercise intolerance. In this context, it remains unknown whether decreased O2 delivery accentuates neuromuscular manifestations of central and peripheral fatigue in coexistent COPD-CHF. If this holds true, it is conceivable that delivering a low-density gas mixture (heliox) through non-invasive positive pressure ventilation could ameliorate cardiopulmonary function/interactions and reduce the work of breathing during exercise in these patients. The major consequence would be increased O2 delivery to the brain and active muscles with potential benefits to exercise capacity (i.e., ↓central and peripheral neuromuscular fatigue, respectively). We therefore hypothesize that patients with coexistent COPD-CHF stop exercising prematurely due to impaired central motor drive and muscle contractility as the cardiorespiratory system fails to deliver sufficient O2 to simultaneously attend the metabolic demands of the brain and the active limb muscles.

Consumption of the dietary flavanol (−)-epicatechin (EPI) is associated with enhanced endothelial function and augmented skeletal muscle capillarity and mitochondrial volume density. The potential for EPI to improve peripheral vascular function and muscle oxygenation during exercise is unknown. We tested the hypothesis that EPI administration in healthy rats would improve treadmill exercise performance secondary to elevated skeletal muscle blood flow and vascular conductance [VC, blood flow/mean arterial pressure (MAP)] and improved skeletal muscle microvascular oxygenation. Rats received water (control, n = 12) or 4 mg/kg EPI ( n = 12) via oral gavage daily for 24 days. Exercise endurance capacity and peak O2 uptake (V̇o2 peak) were measured via treadmill runs to exhaustion. MAP (arterial catheter) and blood flow (radiolabeled microspheres) were measured and VC was calculated during submaximal treadmill exercise (25 m/min, 5% grade). Spinotrapezius muscle microvascular O2 pressure (Po2mv) was measured (phosphorescence quenching) during electrically induced twitch (1 Hz) contractions. In conscious rats, EPI administration resulted in lower (↓∼5%) resting ( P = 0.03) and exercising ( P = 0.04) MAP. There were no differences in exercise endurance capacity, V̇o2 peak, total exercising hindlimb blood flow (control, 154 ± 13; and EPI, 159 ± 8 ml·min−1·100 g−1, P = 0.68), or VC (control, 1.13 ± 0.10; and EPI, 1.24 ± 0.08 ml·min−1·100 g−1·mmHg−1, P = 0.21) between groups. Following anesthesia, EPI resulted in lower MAP (↓∼16%) but did not impact resting Po2mv or any kinetics parameters ( P > 0.05 for all) during muscle contractions compared with control. EPI administration (4 mg·kg−1·day−1) improved modestly cardiovascular function (i.e., ↓MAP) with no impact on exercise performance, total exercising skeletal muscle blood flow and VC, or contracting muscle microvascular oxygenation in healthy rats.

We report recent studies on structure functions of the nucleon and nuclei. First, clustering effects are investigated in the structure function F_2 of Be-9 for explaining an unusual nuclear correction found in a JLab experiment. We propose that high densities created by formation of clustering structure like 2*alpha+neutron in Be-9 is the origin of the unexpected JLab result by using the antisymmetrized molecular dynamics (AMD). There is an approved proposal at JLab to investigate the structure functions of light nuclei including the cluster structure, so that much details will become clear in a few years. Second, tensor-polarized quark and antiquark distributions are obtained by analyzing HERMES measurements on the structure function b_1 for the deuteron. The result suggests a finite tensor polarization for antiquark distributions, which is an interesting topic for further theoretical and experimental investigations. An experimental proposal exists at JLab for measuring b_1 of the deuteron as a new tensor-structure study in 2010's. Furthermore, the antiquark tensor polarization could be measured by polarized deuteron Drell-Yan processes at hadron facilities such as J-PARC and GSI-FAIR. Third, the recent CDF dijet anomaly is investigated within the standard model by considering possible modifications of the strange-quark distribution. We find that the shape of a dijet-mass spectrum changes depending on the strange-quark distribution. It indicates that the CDF excess could be partially explained as a PDF effect, particularly by the strangeness in the nucleon, within the standard model if the excess at m_{jj}~140 GeV is not a sharp peak., 8 pages, LaTeX, to be published in AIP proceedings, 8th Circum-Pan-Pacific Symposium on High Energy Spin Physics, June 20-24, 2011, Cairns, Australia

Semi-inclusive hadron-production processes are becoming important in high-energy hadron reactions. They are used for investigating properties of quark-hadron matters in heavy-ion collisions, for finding the origin of nucleon spin in polarized lepton-nucleon and nucleon-nucleon reactions, and possibly for finding exotic hadrons. In describing the hadron-production cross sections in high-energy reactions, fragmentation functions are essential quantities. A fragmentation function indicates the probability of producing a hadron from a parton in the leading order of the running coupling constant $\alpha_s$. Its $Q^2$ dependence is described by the standard DGLAP (Dokshitzer-Gribov-Lipatov-Altarelli-Parisi) evolution equations, which are often used in theoretical and experimental analyses of the fragmentation functions and in calculating semi-inclusive cross sections. The DGLAP equations are complicated integro-differential equations, which cannot be solved in an analytical method. In this work, a simple method is employed for solving the evolution equations by using Gauss-Legendre quadrature for evaluating integrals, and a useful code is provided for calculating the $Q^2$ evolution of the fragmentation functions in the leading order (LO) and next-to-leading order (NLO) of $\alpha_s$. The renormalization scheme is $\overline{MS}$ in the NLO evolution. Our evolution code is explained for using it in one's studies on the fragmentation functions., Comment: 16 pages, 6 figures, To be published in Computer Physics Communications

We report current status of global analyses on nuclear parton distribution functions (NPDFs). The optimum NPDFs are determined by analyzing high-energy nuclear reaction data. Due to limited experimental measurements, antiquark modifications have large uncertainties at x>0.2 and gluon modifications cannot be determined. A nuclear modification difference between u and d quark distributions could be an origin of the long-standing NuTeV sin^2 theta_w anomaly. There is also an issue of nuclear modification differences between the structure functions of charged-lepton and neutrino reactions. Next, nuclear clustering effects are discussed in structure functions F_2^A as a possible explanation for an anomalous result in the Be-9 nucleus at the Thomas Jefferson National Accelerator Facility (JLab). Last, tensor-polarized quark and antiquark distribution functions are extracted from HERMES data on the polarized structure function b_1 of the deuteron, and they could be used for testing theoretical models and for proposing future experiments, for example, the one at JLab. Such measurements could open a new field of spin physics in spin-one hadrons., 9 pages, LaTeX, 11 eps files, to be published in APS Proceedings of the 3rd International Workshop on Nucleon Structure at Large Bjorken x, Newport News, Virginia, USA, October 13-15, 2010

We discuss studies on determination of fragmentation functions and an application to exotic-hadron search by using characteristic differences between favored and disfavored functions. The optimum fragmentation functions are determined for pion, kaon, and proton in the leading order (LO) and next-to-leading order (NLO) of the running coupling constant alpha_s by global analyses of hadron-production data in electron-positron annihilation. Various parametrization results are much different in disfavored-quark and gluon fragmentation functions; however, we show that they are within uncertainties of the determined functions by using the Hessian method for uncertainty estimation. We find that the uncertainties are especially large in the disfavored-quark and gluon fragmentation functions. NLO improvements are explicitly shown in the determination by comparing uncertainties of the LO and NLO functions. Next, we propose to use differences between favored and disfavored fragmentation functions for determining internal quark configurations of exotic hadrons. We make a global analysis for f_0 (980) for finding its internal configuration; however, uncertainties are too large to specify the structure at this stage., 8 pages, LaTeX, 7 eps files, Progress of Theoretical Physics, Supplement in press. Proceedings of New Frontiers in QCD 2010 - Exotic Hadron Systems and Dense Matter -, Jan.18 - Mar.19, 2010, Kyoto, Japan

The control of vascular tone during exercise is highly complex and integrated. Specifically, in regards to the contribution of nitric oxide (NO), the observed magnitude and muscle fiber-type dependency of the NO contribution to exercise hyperemia may differ depending on the timing of NO synthase (NOS) inhibition with respect to the exercise bout (i.e., administration prior to vs. during exercise). We tested the hypothesis that, in the presence of prior cyclooxygenase inhibition (indomethacin, 5 mg/kg-1), NOS inhibition ( NG-nitro-l-arginine methyl ester, l-NAME; 10 mg/kg) administered during submaximal treadmill exercise would blunt blood flow and vascular conductance (VC) in the hindlimb muscle(s) of the rat with the greatest reductions in blood flow and VC occurring in the predominantly oxidative muscles. Adult female Wistar rats ( n = 10, age: 3–4 mo) ran on a motor-driven treadmill (20 m/min, 10% grade). Total and regional hindlimb muscle blood flow and VC were determined via radiolabeled microspheres before (control) and after l-NAME administration during exercise. l-NAME reduced ( P < 0.05) total hindlimb muscle blood flow (control: 123 ± 10, l-NAME: 103 ± 7 ml·min−1·100g−1) and VC (control: 0.95 ± 0.09, l-NAME: 0.63 ± 0.05 ml·min−1·100g−1·mmHg−1). There was a significant correlation ( r = 0.51, P < 0.05) between the absolute reductions in VC after l-NAME and the percent sum of type I and IIa fibers in the individual muscles and muscle parts; however, there was no correlation ( P = 0.62) when expressed as blood flow. Surprisingly, the highly oxidative muscles demonstrated a marked ability to maintain oxygen delivery, which differs substantially from previous reports of l-NAME infusion prior to exercise in these muscles. The demonstration that NO is an important regulator of blood flow and VC in the rat hindlimb during treadmill exercise, but that the fiber-type dependency of NO is altered markedly when NOS inhibition is performed during, vs. prior to, exercise, lends important insights into the integrated nature of vascular control during exercise.

We explain the current status of nuclear parton distribution functions in connection with neutrino-nucleus interactions. Neutrino deep inelastic scattering (DIS) measurements have been done for heavy nuclear targets such as iron and lead. In order to extract structure functions of the nucleon, one needs to remove nuclear effects from the data. However, recent studies indicate that there are inconsistencies in nuclear modifications between charged-lepton and neutrino scattering measurements. Nuclear medium effects could be also an origin for the NuTeV anomaly in the weak-mixing angle. In addition, the modifications could affect neutrino-oscillation experiments because some DIS events of neutrino-oxygen nucleus interactions are contained. On the other hand, the nuclear medium effects themselves are interesting and important for describing nuclei in terms of quark and gluon degrees of freedom., 8 pages, LaTeX, 9 eps files, to be published in AIP conference proceedings

We investigate impact of $\pi^0$-production data at Relativistic Heavy Ion Collider (RHIC) and future E07-011 experiment for the structure function $g_1$ of the deuteron at the Thomas Jefferson National Accelerator Facility (JLab) on studies of nucleonic spin structure, especially on the polarized gluon distribution function. By global analyses of polarized lepton-nucleon scattering and the $\pi^0$-production data, polarized parton distribution functions are determined and their uncertainties are estimated by the Hessian method. Two types of the gluon distribution function are investigated. One is a positive distribution and the other is a node-type distribution which changes sign at $x \sim 0.1$. Although the RHIC $\pi^0$ data seem to favor the node type for $\Delta g(x)$, it is difficult to determine a precise functional form from the current data. However, it is interesting to find that the gluon distribution $\Delta g(x)$ is positive at large $x$ ($>0.2$) due to constraints from the scaling violation in $g_1$ and RHIC $\pi^0$ data. The JLab-E07-011 measurements for $g_1^d$ should be also able to reduce the gluon uncertainty, and the reduction is comparable to the one by RUN-5 $\pi^0$-production data at RHIC. The reduction is caused by the error correlation between polarized antiquark and gluon distributions and by a next-to-leading-order (NLO) gluonic effect in the structure function $g_1^d$. We find that the JLab-E07-011 data are accurate enough to probe the NLO gluonic term in $g_1$. Both RHIC and JLab data contribute to better determination of the polarized gluon distribution in addition to improvement on polarized quark and antiquark distributions., Comment: 11 pages, 9 eps figures, To be published in Nuclear Physics B. AAC08 FORTRAN package is available at the web site http://spin.riken.bnl.gov/aac/

We discuss internal structure of an exotic hadron by using fragmentation functions. The fragmentation functions for the f_0(980) meson are obtained by a global analysis of e^++e^- \to f_0+X data. Quark configuration of the f_0(980) could be determined by peak positions and second moments of the obtained fragmentation functions., 4page, 2eps figures, To appear in the proceedings of Chiral Symmetry in Hadron and Nuclear Physics (Chiral 07), Osaka, Japan, 13-16 Nov. 2007

Fragmentation functions and their uncertainties are determined for pion, kaon, and proton by a global $��^2$ analysis of charged-hadron production data in electron-positron annihilation and by the Hessian method for error estimation. It is especially important that the uncertainties of the fragmentation functions are estimated in this analysis. The results indicate that the fragmentation functions, especially gluon and light-quark fragmentation functions, have large uncertainties at small $Q^2$. There are large differences between widely-used functions by KKP (Kniehl, Kramer, and P��tter) and Kretzer; however, they are compatible with each other and also with our functions if the uncertainties are taken into account. We find that determination of the fragmentation functions is improved in next-to-leading-order (NLO) analyses for the pion and kaon in comparison with leading-order ones. Such a NLO improvement is not obvious in the proton. Since the uncertainties are large at small $Q^2$, the uncertainty estimation is very important for analyzing hadron-production data at small $Q^2$ or $p_T$ ($Q^2, p_T^2 << M_Z^2$) in lepton scattering and hadron-hadron collisions. A code is available for general users for calculating obtained fragmentation functions., 16 pages, 15 figures, revtex. to be published in Phys. Rev. D

Global analysis has been performed within the next-to-leading order in Quantum Chromodynamics (QCD) to determine polarized parton distributions with new experimental data in spin asymmetries. The new data set includes JLab, HERMES, and COMPASS measurements on spin asymmetry A_1 for the neutron and deuteron in lepton scattering. Our new analysis also utilizes the double-spin asymmetry for pi^0 production in polarized pp collisions, A_{LL}^{pi^0}, measured by the PHENIX collaboration. Because of these new data, uncertainties of the polarized PDFs are reduced. In particular, the JLab, HERMES, and COMPASS measurements are valuable for determining Delta d_v(x) at large x and Delta qbar(x) at x~0.1. The PHENIX pi^0 data significantly reduce the uncertainty of Delta g(x). Furthermore, we discuss a possible constraint on Delta g(x) at large x by using the HERMES data on g_1^d in comparison with the COMPASS ones at x~0.05., 11 pages, REVTeX, 13 eps files, Phys. Rev. D in press

We report global analysis results for polarized parton distribution functions in the nucleon. The optimum distributions are determined by using spin asymmetry data on polarized lepton scattering on proton, neutron, and deuteron. Their uncertainties are estimated by the Hessian method. As a result, polarized quark distributions are relatively well determined, whereas the polarized gluon distribution has a large uncertainty band. We find that the obtained gluon distribution is compatible with recent \Delta g/g measurements in high-p_T hadron productions., Comment: 3 pages, 2 figures, to be published in the proceedings of the XVIIth Particles and Nuclei International Conference (PANIC), Santa Fe, New Mexico, USA, October 24-28, 2005

Addition of (LiF)$_{y, 28 pages, accepted to J. Supercond

We report global analysis results of experimental data for nuclear structure-function ratios F_2^A/F_2^{A'} and proton-nucleus Drell-Yan cross-section ratios sigma_{DY}^{pA}/sigma_{DY}^{pA'} in order to determine optimum parton distribution functions (PDFs) in nuclei. An important point of this analysis is to show uncertainties of the distributions by the Hessian method. The results indicate that the uncertainties are large for gluon distributions in the whole x region and for antiquark distributions at x>0.2. We provide a code for calculating any nuclear PDFs at given x and Q^2 for general users. They can be used for calculating high-energy nuclear reactions including neutrino-nucleus interactions, which are discussed at this workshop., 1+6 pages, LaTeX, 10 eps files, espcrc2.sty, to be published in Nucl. Phys. B Supplements, Proceedings of the Third International Workshop on Neutrino-Nucleus Interactions in the Few GeV Region (NuInt04), Gran Sasso, Italy, March 17-21, 2004. Nuclear PDF library is available at http://hs.phys.saga-u.ac.jp/nuclp.html

Optimum nuclear parton distributions are obtained by analyzing available experimental data on electron and muon deep inelastic scattering (DIS). The distributions are given at Q^2=1 GeV^2 with a number of parameters, which are determined by a chi^2 analysis of the data. Valence-quark distributions are relatively well determined at medium x, but they are slightly dependent on the assumed parametrization form particularly at small x. Although antiquark distributions are shadowed at small x, their behavior is not obvious at medium x from the F_2 data. The gluon distributions could not be restricted well by the inclusive DIS data; however, the analysis tends to support the gluon shadowing at small x. We provide analytical expressions and computer subroutines for calculating the nuclear parton distributions, so that other researchers could use them for applications to other high-energy nuclear reactions., 1+11 pages, LaTeX, amsmath.sty, wrapfig.sty, graphicx.sty, ias.cls, ias.sty, pramana.sty, pmana10.sty, pbib.sty, times.sty, 9 eps figures. Invited talk given at the International Symposium on Nuclear Physics, Mumbai, India, Dec. 18-22, 2000, to be published in proceedings. Complete postscript file is available at http://www-hs.phys.saga-u.ac.jp Email: hirai@hsg.phys.saga-u.ac.jp, kumanos@cc.saga-u.ac.jp, miyama@comp.metro-u.ac.jp

Parametrization of nuclear parton distributions is investigated in the leading order of alpha_s. The parton distributions are provided at Q^2=1 GeV^2 with a number of parameters, which are determined by a chi^2 analysis of the data on nuclear structure functions. Quadratic or cubic functional form is assumed for the initial distributions. Although valence quark distributions in the medium x region are relatively well determined, the small x distributions depend slightly on the assumed functional form. It is difficult to determine the antiquark distributions at medium x and gluon distributions. From the analysis, we propose parton distributions at Q^2=1 GeV^2 for nuclei from deuteron to heavy ones with the mass number A~208. They are provided either analytical expressions or computer subroutines for practical usage. Our studies should be important for understanding the physics mechanism of the nuclear modification and also for applications to heavy-ion reactions. This kind of nuclear parametrization should also affect existing parametrization studies in the nucleon because "nuclear" data are partially used for obtaining the optimum distributions in the "nucleon"., 16 pages, REVTeX4b5, revtex4.cls, url.sty, natbib.sty, 10pt.rtx, aps.rtx, revsymb.sty, 21 eps figures. Submitted for publication. Computer codes for the nuclear parton distributions could be obtained from http://www-hs.phys.saga-u.ac.jp Email: kumanos@cc.saga-u.ac.jp

The halo structure of the neutron-dripline nucleus 14Be has been investigated by various approaches, such as the interaction cross section measurement, dissociation reaction and 14Be fragmentation. In the recent plausible view, the mixing of s and d-wave components in the halo wave function has been suggested. In the present study, the halo structure of 14Be was investigated by measuring its Isobaric Analog State (IAS). Since the wave function of the IAS is essentially the same as that of its isobaric partner, possible exotic natures of 14Be may be traced in properties of the IAS such as the Coulomb displacement energy (ΔE C) and the width of the IAS. The IAS of the 14Be was excited by the charge-exchange reaction which was successfully applied to the neutron-dripline nucleus 11Li and obtained the halo properties [1, 2]. In the present study, applying this reaction to 14Be, we have measured the 14Be(p,n)14B* reaction in inverse kinematics at E in = 74 A MeV [3].

Polarized parton distribution functions are determined by using asymmetry A_1 data from longitudinally polarized deep inelastic scattering experiments. From our \chi^2 analysis, polarized u-valence, d-valence, antiquark, and gluon distributions are obtained. We propose one set of leading-order distributions and two sets of next-to-leading-order ones as the longitudinally-polarized parton distribution functions., Comment: 1+6 pages LATEX, sprocl.sty, epsfig.sty, wrapfig.sty, 4 eps figures. Talk at the RCNP-TMU Symposium on "Spins in Nuclear and Hadronic Reactions", Tokyo, Japan, Oct.26-28, 1999, to be published in proceedings. Complete postscript file is available at http://www-hs.phys.saga-u.ac.jp Email: 98td25@edu.cc.saga-u.ac.jp

We investigate numerical solution of the Dokshitzer-Gribov-Lipatov-Altarelli- Parisi (DGLAP) Q^2 evolution equation for the transversity distribution Delta_T q or the structure function h_1. The leading-order (LO) and next-to- leading-order (NLO) evolution equations are studied. The renormalization scheme is MS or overline{MS} in the NLO case. Dividing the variables x and Q^2 into small steps, we solve the integrodifferential equations by the Euler method in the variable Q^2 and by the Simpson method in the variable x. Numerical results indicate that accuracy is better than 1% in the region 10^{-5}, Comment: 1+29 pages, LaTeX2e, epsfig.sty, amsmath.sty, 6 eps figures. Submitted for publication. Complete postscript file is available at ftp://ftp.cc.saga-u.ac.jp/pub/paper/riko/quantum1 or at http://www.cc.saga-u.ac.jp/saga-u/riko/physics/quantum1/structure.html Our evolution program may be obtained upon email request. (See the WWW home page for the details.) Email: 96sm18@edu.cc.saga-u.ac.jp, kumanos@cc.saga-u.ac.jp, 96td25@edu.cc.saga-u.ac.jp

Tumor necrosis factor (TNF) is a monocyte-derived protein cytotoxic or cytostatic for some tumor cell lines. Here we show that highly purified E. coli-derived recombinant human TNF stimulated the growth of human FS-4 diploid fibroblasts. Stimulation of cell growth was demonstrable at a TNF concentration of 10 pg/ml (3 X 10(-13) M). Maximal stimulation was attained at TNF concentrations of 10 ng/ml (3 X 10(-10) M) or higher. Growth-stimulatory activity of TNF was inhibited by an mAb neutralizing the cytotoxic activity of TNF. Growth stimulation was not inhibited by another mAb specific for TNF, lacking neutralizing activity for the cytotoxic activity of TNF. Growth stimulation by TNF was more marked and more sustained in the presence of greater than or equal to 10% FCS than in medium with less than or equal to 5% FCS. Addition of TNF to confluent FS-4 cultures also produced a marked stimulation of cell growth in the presence of fresh FCS, while a much less marked stimulation was seen in the absence of FCS. Stimulation of confluent cultures by TNF in serum-free medium was enhanced by insulin, suggesting that insulin or insulin-like growth factor(s) in the serum can act synergistically with TNF in producing growth stimulation. While the growth-stimulatory effects of TNF and insulin were synergistic, the actions of TNF and epidermal growth factor (EGF) were less than additive, suggesting that TNF and EGF may activate identical or similar pathways. We conclude that stimulation of cell growth is probably a physiological function of TNF, and that the cytotoxic and cytostatic actions of TNF may be the result of an anomalous growth signal transduction in neoplastic cells lacking the constraints of normal growth control mechanisms.

[This corrects the article DOI: 10.1371/journal.pone.0244464.]., (Copyright: © 2024 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)