Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The ...asymmetry depends on the azimuthal angles of both the pion (phi) and the target spin axis (phi(S)) about the virtual-photon direction and relative to the lepton scattering plane. The extracted Fourier component sin((phi+phi(S))(pi)(UT) is a signal of the previously unmeasured quark transversity distribution, in conjunction with the Collins fragmentation function, also unknown. The component sin((phi-phi(S)(pi)(UT) arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson production.
► We examined the role of mTOR in fear memory. ► Rapamycin in the amygdala or hippocampus around training or retrieval impaired memory. ► mTOR in the amygdala and hippocampus is involved in fear ...memory reconsolidation.
Mammalian target of rapamycin (mTOR), a central regulator of protein synthesis in neurons, has been implicated in synaptic plasticity and memory. Here we show that mTOR inhibition by rapamycin in the basolateral amygdala (BLA) or dorsal hippocampus (DH) impairs both formation and reconsolidation of memory for inhibitory avoidance (IA) in rats. Male Wistar rats received bilateral infusions of vehicle or rapamycin into the BLA or DH before or after IA training or retrieval. Memory retention was tested at different time points after drug infusion. Rapamycin impaired long-term IA retention when given before or immediately after training or retrieval into the BLA. When infused into the DH, rapamycin produced memory impairment when given before training or immediately after retrieval. The impairing effects of post-retrieval rapamycin required memory retrieval and were not reversed by a reminder shock. The results provide the first evidence that mTOR in the BLA and DH might play a role in IA memory reconsolidation.
► Sodium butyrate ameliorated an aging-associated recognition memory deficit in rats. ► The memory-improving effect was produced by an injection given early after training. ► Histone deacetylase ...inhibitors can act on consolidation to rescue memory dysfunction.
Here we show that a systemic injection of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) ameliorated an aging-associated deficit in object recognition memory in rats when the injection was given immediately, but not 6
h after training. NaB had no effect in younger rats with normal memory retention. The results indicate that HDACis can ameliorate aging-related memory impairments by influencing the early consolidation phase of memory formation.
A
bstract
Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted from the H
ermes
...data set of 2006-2007 using a missing-mass event selection technique. The asymmetry amplitudes extracted from this data set are more precise than those extracted from the earlier data set of 1996-2005 previously analysed in the same manner by H
ermes
. The results from the two data sets are compatible with each other. Results from these combined data sets are extracted and constitute the most precise asymmetry amplitude measurements made in the H
ermes
kinematic region using a missing-mass event selection technique.
A measurement of the beam-spin asymmetry in the azimuthal distribution of pions produced in semi-inclusive deep-inelastic scattering off protons is presented. The measurement was performed using the ...HERMES spectrometer with a hydrogen gas target and the longitudinally polarized 27.6 GeV positron beam of HERA. The sinusoidal amplitude of the dependence of the asymmetry on the angle ϕ of the hadron production plane around the virtual photon direction relative to the lepton scattering plane was measured for π+, π− and π0 mesons. The dependence of this amplitude on the Bjorken scaling variable and on the pion fractional energy and transverse momentum is presented. The results are compared to theoretical model calculations.
The species Azospirillum amazonense belongs to a well-known genus of plant growth-promoting bacteria. This bacterium is found in association with several crops of economic importance; however, there ...is a lack of information on its physiology. In this work, we present a comprehensive analysis of the genomic features of this species.
Genes of A. amazonense related to nitrogen/carbon metabolism, energy production, phytohormone production, transport, quorum sensing, antibiotic resistance, chemotaxis/motility and bacteriophytochrome biosynthesis were identified. Noteworthy genes were the nitrogen fixation genes and the nitrilase gene, which could be directly implicated in plant growth promotion, and the carbon fixation genes, which had previously been poorly investigated in this genus. One important finding was that some A. amazonense genes, like the nitrogenase genes and RubisCO genes, were closer phylogenetically to Rhizobiales members than to species of its own order.
The species A. amazonense presents a versatile repertoire of genes crucial for its plant-associated lifestyle.
Exclusive electroproduction of
ω
mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of
Q
2
>
1.0
GeV
2
, 3.0 GeV
<
W
<
6.3 GeV, and
-
t
′
<
0.2
GeV
2
. ...Results on the angular distribution of the
ω
meson, including its decay products, are presented. The data were accumulated with the HERMES forward spectrometer during the 1996–2007 running period using the 27.6 GeV longitudinally polarized electron or positron beam of HERA. The determination of the virtual-photon longitudinal-to-transverse cross-section ratio reveals that a considerable part of the cross section arises from transversely polarized photons. Spin density matrix elements are presented in projections of
Q
2
or
-
t
′
. Violation of
s
-channel helicity conservation is observed for some of these elements. A sizable contribution from unnatural-parity-exchange amplitudes is found and the phase shift between those amplitudes that describe transverse
ω
production by longitudinal and transverse virtual photons,
γ
L
∗
→
ω
T
and
γ
T
∗
→
ω
T
, is determined for the first time. A hierarchy of helicity amplitudes is established, which mainly means that the unnatural-parity-exchange amplitude describing the
γ
T
∗
→
ω
T
transition dominates over the two natural-parity-exchange amplitudes describing the
γ
L
∗
→
ω
L
and
γ
T
∗
→
ω
T
transitions, with the latter two being of similar magnitude. Good agreement is found between the HERMES proton data and results of a pQCD-inspired phenomenological model that includes pion-pole contributions, which are of unnatural parity.
A
bstract
The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized Hera positron beam scattering off an unpolarized hydrogen target is measured at ...Hermes. The asymmetry arises from deeply virtual Compton scattering and its interference with the Bethe-Heitler process. Azimuthal amplitudes of the beam-helicity asymmetry are extracted from a data sample consisting of
ep
→
epγ
events with detection of all particles in the final state including the recoiling proton. The installation of a recoil detector, while reducing the acceptance of the experiment, allows the elimination of background from
ep
→
eN πγ
events, which was estimated to contribute an average of about 12% to the signal in previous Hermes publications. The removal of this background from the present data sample is shown to increase the magnitude of the leading asymmetry amplitude by 0
.
054 ± 0
.
016 to −0
.
328 ± 0
.
027 (stat
.
) ± 0
.
045 (syst
.
).
UV filters represent a new class of endocrine active chemicals. In vitro, 8/9 chemicals showed estrogenic (MCF-7 cells), and 2/9 antiandrogenic activity (MDA-kb2 cells). Six/nine filters ...(benzophenone (Bp)-1, Bp-2, Bp-3, 3-benzylidene camphor (3-BC), 4-methylbenzylidene camphor (4-MBC), octyl-methoxycinnamate (OMC)) increased uterine weight in immature rats. 3-Benzylidene camphor and 4-MBC displaced 16α
125I-estradiol from human estrogen receptor (ER)β , not ERα. Developmental toxicity of 4-MBC (0.7–47
mg/kg body weight/day) and 3-BC (0.24–7
mg/kg), administered in chow was investigated in Long Evans (LE) rats. Weight gain of pregnant rats was reduced only by 3-BC, early postnatal survival rate and thymus weight by both compounds at higher doses. 4-Methylbenzylidene camphor and 3-BC delayed male puberty, and dose-dependently affected reproductive organ weights of adult male and female F1 offspring, with partly different effect patterns. Thyroid weight was increased by higher 4-MBC doses. Tissue-specific changes in mRNA levels of estrogen-regulated genes in prostate, uterus and brain regions, determined by real-time PCR, and in their response to acute estradiol challenge in adult gonadectomized offspring were observed. Lowest effective doses were 0.24
mg/kg/day for 3-BC and 7
mg/kg/day for 4-MBC. Fat tissue levels at 7
mg/kg 4-MBC (GC–MS) approached the range of UV filters in fish (Nagtegaal et al., 1997; Balmer et al., 2004).
Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons and electrons off a transversely nuclear-polarized hydrogen target. The ...dependence of the cross section on the azimuthal angles of the target polarization (ϕS) and the produced hadron (ϕ) is found to have a substantial sin(ϕ+ϕS) modulation for the production of π+, π− and K+. This Fourier component can be interpreted in terms of non-zero transversity distribution functions and non-zero favored and disfavored Collins fragmentation functions with opposite sign. For π0 and K− production the amplitude of this Fourier component is consistent with zero.
PDF
