We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q\(^2\)) up to 15.75~\gevsq. Combined with existing data, these provide an ...improved extraction of the proton magnetic form factor at high Q\(^2\) and double the range over which a longitudinal/transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q\(^2\) and attributed to hard two-photon exchange (TPE) effects, extending to 8~(GeV/c)\(^2\) the range of Q\(^2\) for which a discrepancy is established at \(>\)95\% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q\(^2\).
We report high-precision measurements of the Deeply Virtual Compton
Scattering (DVCS) cross section at high values of the Bjorken variable $x_B$.
DVCS is sensitive to the Generalized Parton ...Distributions of the nucleon, which
provide a three-dimensional description of its internal constituents. Using the
exact analytic expression of the DVCS cross section for all possible
polarization states of the initial and final electron and nucleon, and final
state photon, we present the first experimental extraction of all four
helicity-conserving Compton Form Factors (CFFs) of the nucleon as a function of
$x_B$, while systematically including helicity flip amplitudes. In particular,
the high accuracy of the present data demonstrates sensitivity to some very
poorly known CFFs.
Phys. Rev. Lett. 127, 152301 (2021) We report measurements of the exclusive neutral pion electroproduction cross
section off protons at large values of $x_B$ (0.36, 0.48 and 0.60) and $Q^2$
(3.1 to ...8.4 GeV$^2$) obtained from Jefferson Lab Hall A experiment E12-06-014.
The corresponding structure functions $d\sigma_L/dt+\epsilon d\sigma_T/dt$,
$d\sigma_{TT}/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{LT'}/dt$ are extracted as a
function of the proton momentum transfer $t-t_{min}$. The results suggest the
amplitude for transversely polarized virtual photons continues to dominate the
cross-section throughout this kinematic range. The data are well described by
calculations based on transversity Generalized Parton Distributions coupled to
a helicity flip Distribution Amplitude of the pion, thus providing a unique way
to probe the structure of the nucleon.
Hadronic reactions producing strange quarks such as exclusive or semi-inclusive kaon production, play an important role in studies of hadron structure and the dynamics that bind the most basic ...elements of nuclear physics. The small-angle capability of the new Super High Momentum Spectrometer (SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated 11-GeV beam energy in Hall C - and coincidence capability with the well-understood High Momentum Spectrometer, will allow for probes of such hadron structure involving strangeness down to the smallest distance scales to date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has been constructed for the SHMS. The detector consists of an aerogel tray followed by a diffusion box. Four trays for aerogel of nominal refractive indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray combination will allow for identification of kaons from 1 GeV/c up to 7.2 GeV/c, reaching 10^-2 proton and 10^-3 pion rejection, with kaon detection efficiency better than 95%. The diffusion box of the detector is equipped with 14 five-inch diameter photomultiplier tubes. Its interior walls are covered with Gore diffusive reflector, which is superior to the commonly used Millipore paper and improved the detector performance by 35%. The inner surface of the two aerogel trays with higher refractive index is covered with Millipore paper, however, those two trays with lower aerogel refractive index are again covered with Gore diffusive reflector for higher performance. The measured mean number of photoelectrons in saturation is ~12 for n=1.030, ~sim8 for n=1.020, ~10 for n=1.015, and ~5.5 for n=1.011. The design details, the results of component characterization, and initial performance tests and optimization of the detector are presented.
We report high-precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section at high values of the Bjorken variable \(x_B\). DVCS is sensitive to the Generalized Parton ...Distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton Form Factors (CFFs) of the nucleon as a function of \(x_B\), while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.
We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of \(x_B\) (0.36, 0.48 and 0.60) and \(Q^2\) (3.1 to 8.4 GeV\(^2\)) obtained from ...Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions \(d\sigma_L/dt+\epsilon d\sigma_T/dt\), \(d\sigma_{TT}/dt\), \(d\sigma_{LT}/dt\) and \(d\sigma_{LT'}/dt\) are extracted as a function of the proton momentum transfer \(t-t_{min}\). The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross-section throughout this kinematic range. The data are well described by calculations based on transversity Generalized Parton Distributions coupled to a helicity flip Distribution Amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.
Oleanolic acid (OA), a natural pentacyclic triterpenoid, has been reported to exert protective effects against several neurological diseases through its anti-oxidative and anti-inflammatory ...activities. The goal of the present study was to evaluate the therapeutic potential of OA against acute and chronic brain injuries after ischemic stroke using a mouse model of transient middle cerebral artery occlusion (tMCAO, MCAO/reperfusion). OA administration immediately after reperfusion significantly attenuated acute brain injuries including brain infarction, functional neurological deficits, and neuronal apoptosis. Moreover, delayed administration of OA (at 3 h after reperfusion) attenuated brain infarction and improved functional neurological deficits during the acute phase. Such neuroprotective effects were associated with attenuation of microglial activation and lipid peroxidation in the injured brain after the tMCAO challenge. OA also attenuated NLRP3 inflammasome activation in activated microglia during the acute phase. In addition, daily administration of OA for 7 days starting from either immediately after reperfusion or 1 day after reperfusion significantly improved functional neurological deficits and attenuated brain tissue loss up to 21 days after the tMCAO challenge; these findings supported therapeutic effects of OA against ischemic stroke-induced chronic brain injury. Together, these findings showed that OA exerted neuroprotective effects against both acute and chronic brain injuries after tMCAO challenge, suggesting that OA is a potential therapeutic agent to treat ischemic stroke.
Effects of foreign direct investment (FDI) and income on pollution emissions are examined using time series data from 1980 to 2010 for 14 Latin American countries. Specifically, we test the validity ...of Pollution Haven Hypothesis (PHH) and Environmental Kuznets Curve (EKC) hypothesis for this region. Results from panel fixed and random effects models that controlled the effects of physical capital, energy, human capital, population density, and unemployment rate indicate the validity of both the PHH and EKC hypothesis. Estimating two separate models for high and low-income countries does not alter the findings for the PHH, however, the impacts of human capital on pollution emission are found to be different for the two groups of countries. Policies that focus on attracting clean and energy efficient industries through FDI have potential to improve environmental health while enhancing economic growth in Latin America.
•The Pollution Haven and EKC hypotheses are tested for Latin America.•Effects of physical and human capital, energy, and unemployment rate are controlled.•Results indicate the validity of both the PHH and EKC hypotheses.•Impact of human capital on pollution differs by per capita income.•Policies attracting clean and energy efficient industries through FDI seem useful.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Multiple sclerosis (MS) is an autoimmune disease characterized by progressive neuronal loss, neuroinflammation, axonal degeneration, and demyelination. Previous studies have reported that 6-shogaol, ...a major constituent of ginger (Zingiber officinale rhizome), and its biological metabolite, 6-paradol, have anti-inflammatory and anti-oxidative properties in the central nervous system (CNS). In the present study, we investigated whether 6-shogaol and 6-paradol could ameliorate against experimental autoimmune encephalomyelitis (EAE), a mouse model of MS elicited by myelin oligodendrocyte glycoprotein (MOG 35-55 ) peptide immunization with injection of pertussis toxin. Once-daily administration of 6-shogaol and 6-paradol (5 mg/kg/day, p.o.) to symptomatic EAE mice significantly alleviated clinical signs of the disease along with remyelination and reduced cell accumulation in the white matter of spinal cord. Administration of 6-shogaol and 6-paradol into EAE mice markedly reduced astrogliosis and microglial activation as key features of immune responses inside the CNS. Furthermore, administration of these two molecules significantly suppressed expression level of tumor necrosis factor-α, a major proinflammatory cytokine, in EAE spinal cord. Collectively, these results demonstrate therapeutic efficacy of 6-shogaol or 6-paradol for EAE by reducing neuroinflammatory responses, further indicating the therapeutic potential of these two active ingredients of ginger for MS.
In this work, I studied whether news media sentiments have an impact on Bitcoin volatility. In doing so, I applied three different range-based volatility estimates along with two different ...sentiments, namely psychological sentiments and financial sentiments, incorporating four various sentiment dictionaries. By analyzing 17,490 news coverages by 91 major English-language newspapers listed in the LexisNexis database from around the globe from January 2012 until August 2021, I found news media sentiments to play a significant role in Bitcoin volatility. Following the heterogeneous autoregressive model for realized volatility (HAR-RV)—which uses the heterogeneous market idea to create a simple additive volatility model at different scales to learn which factor is influencing the time series—along with news sentiments as explanatory variables, showed a better fit and higher forecasting accuracy. Furthermore, I also found that psychological sentiments have medium-term and financial sentiments have long-term effects on Bitcoin volatility. Moreover, the National Research Council Emotion Lexicon showed the main emotional drivers of Bitcoin volatility to be anticipation and trust.
•In this work, I studied whether news media sentiments have an impact on Bitcoin volatility.•Analyzed 17,490 news items on Bitcoin by major English-language newspapers using two categories of sentiment dictionaries.•I extended the heterogeneous autoregressive model for realized volatility with psychological and financial sentiments.•I found psychological sentiments have medium-term and financial sentiments have long-term effects on Bitcoin volatility.•The emotion lexicon showed the main drivers of Bitcoin volatility to be anticipation and trust of the optimistic investors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
