Two-Particle Interference of Electron Pairs on a Molecular Level

We investigate the photodouble ionization of H_{2} molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasiparticle consisting of both electrons (i.e., the "dielectron") does. The work highlights the fact that nonlocal effects are embedded everywhere in nature where many-particle processes are involved.

Smoking and Posttraumatic Stress Disorder Symptomatology in Orofacial Pain

To explore the impact of interactions between smoking and symptoms of posttraumatic stress disorder (PTSD) on pain intensity, psychological distress, and pain-related functioning in patients with orofacial pain, a retrospective review was conducted of data obtained during evaluations of 610 new patients with a temporomandibular disorder who also reported a history of a traumatic event. Pain-related outcomes included measures of pain intensity, psychological distress, and pain-related functioning. Main effects of smoking status and PTSD symptom severity on pain-related outcomes were evaluated with linear regression analyses. Further analyses tested interactions between smoking status and PTSD symptom severity on pain-related outcomes. PTSD symptom severity and smoking predicted worse pain-related outcomes. Interaction analyses between PTSD symptom severity and smoking status revealed that smoking attenuated the impact of PTSD symptom severity on affective distress, although this effect was not found at high levels of PTSD symptom severity. No other significant interactions were found, but the present results identifying smoking as an ineffective coping mechanism and the likely role of inaccurate outcome expectancies support the importance of smoking cessation efforts in patients with orofacial pain. Smoking is a maladaptive mechanism for coping with pain that carries significant health- and pain-related risks while failing to fulfill smokers' expectations of affect regulation, particularly among persons with orofacial pain who also have high levels of PTSD symptom severity. Addressing smoking cessation is a critical component of comprehensive treatment. Further research is needed to develop more effective ways to help patients with pain and/or PTSD to replace smoking with more effective coping strategies.

Observation of an Anomalous Line Shape of the η^{'}π^{+}π^{-} Mass Spectrum near the pp[over ¯] Mass Threshold in J/ψ→γη^{'}π^{+}π^{-}

Using 1.09×10^{9} J/ψ events collected by the BESIII experiment in 2012, we study the J/ψ→γη^{'}π^{+}π^{-} process and observe a significant abrupt change in the slope of the η^{'}π^{+}π^{-} invariant mass distribution at the proton-antiproton (pp[over ¯]) mass threshold. We use two models to characterize the η^{'}π^{+}π^{-} line shape around 1.85  GeV/c^{2}: one that explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatté formula), and another that is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85  GeV/c^{2} with strong couplings to the pp[over ¯] final states or a narrow state just below the pp[over ¯] mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a pp[over ¯] moleculelike state or bound state with greater than 7σ significance.

Observation of h_{c} Radiative Decay h_{c}→γη^{'} and Evidence for h_{c}→γη

A search for radiative decays of the P-wave spin singlet charmonium resonance h_{c} is performed based on 4.48×10^{8} ψ^{'} events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels h_{c}→γη^{'} and γη are observed with a statistical significance of 8.4σ and 4.0σ, respectively, for the first time. The branching fractions of h_{c}→γη^{'} and h_{c}→γη are measured to be B(h_{c}→γη^{'})=(1.52±0.27±0.29)×10^{-3} and B(h_{c}→γη)=(4.7±1.5±1.4)×10^{-4}, respectively, where the first errors are statistical and the second are systematic uncertainties.

A phase II study of axitinib in advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) are highly vascular neoplasms overexpressing vascular endothelial growth factor (VEGF) as well as VEGF receptors (VEGFR). Axitinib is a potent, selective inhibitor of VEGFR-1, -2 and -3, currently approved for the treatment of advanced renal cell carcinoma. We performed an open-label, two-stage design, phase II trial of axitinib 5mg twice daily in patients with progressive unresectable/metastatic low-to-intermediate grade carcinoid tumors. The primary end points were progression-free survival (PFS) and 12-month PFS rate. The secondary end points included time to treatment failure (TTF), overall survival (OS), overall radiographic response rate (ORR), biochemical response rate and safety. A total of 30 patients were enrolled and assessable for toxicity; 22 patients were assessable for response. After a median follow-up of 29months, we observed a median PFS of 26.7months (95% CI, 11.4-35.1), with a 12-month PFS rate of 74.5% (±10.2). The median OS was 45.3 months (95% CI, 24.4-45.3), and the median TTF was 9.6months (95% CI, 5.5-12). The best radiographic response was partial response (PR) in 1/30 (3%) and stable disease (SD) in 21/30 patients (70%); 8/30 patients (27%) were unevaluable due to early withdrawal due to toxicity. Hypertension was the most common toxicity that developed in 27 patients (90%). Grade 3/4 hypertension was recorded in 19 patients (63%), leading to treatment discontinuation in six patients (20%). Although axitinib appears to have an inhibitory effect on tumor growth in patients with advanced, progressive carcinoid tumors, the high rate of grade 3/4 hypertension may represent a potential impediment to its use in unselected patients.

Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings

Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years' publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.

Analyzing diffuse scattering with supercomputers. Corrigendum

Errors in the paper by Michels-Clark, Lynch, Hoffmann, Hauser, Weber, Harrison & Bürgi [J. Appl. Cryst. (2013), 46, 1616–1625] are corrected.

Observation of the Singly Cabibbo-Suppressed Decay D^{+}→ωπ^{+} and Evidence for D^{0}→ωπ^{0}

Based on 2.93  fb^{-1} e^{+}e^{-} collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D^{+}→ωπ^{+} and D^{0}→ωπ^{0}. A double tag technique is used to measure the absolute branching fractions B(D^{+}→ωπ^{+})=(2.79±0.57±0.16)×10^{-4} and B(D^{0}→ωπ^{0})=(1.17±0.34±0.07)×10^{-4}, with statistical significances of 5.5σ and 4.1σ, where the first and second uncertainties are statistical and systematic, respectively.

Measurements of Absolute Hadronic Branching Fractions of the Λ_{c}^{+} Baryon

We report the first measurement of absolute hadronic branching fractions of Λ_{c}^{+} baryon at the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold, in the 30 years since the Λ_{c}^{+} discovery. In total, 12 Cabibbo-favored Λ_{c}^{+} hadronic decay modes are analyzed with a double-tag technique, based on a sample of 567  pb^{-1} of e^{+}e^{-} collisions at sqrt[s]=4.599  GeV recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve Λ_{c}^{+} decay modes, the branching fraction for Λ_{c}^{+}→pK^{-}π^{+} is determined to be (5.84±0.27±0.23)%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved.

Measurement of Azimuthal Asymmetries in Inclusive Charged Dipion Production in e^{+}e^{-} Annihilations at sqrt[s]=3.65 GeV

We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e^{+}e^{-}→ππX, based on a data set of 62  pb^{-1} at the center-of-mass energy of 3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.

Electron Localization in Dissociating H_{2}^{+} by Retroaction of a Photoelectron onto Its Source

We investigate the dissociation of H_{2}^{+} into a proton and a H^{0} after single ionization with photons of an energy close to the threshold. We find that the p^{+} and the H^{0} do not emerge symmetrically in the case of the H_{2}^{+} dissociating along the 1sσ_{g} ground state. Instead, a preference for the ejection of the p^{+} in the direction of the escaping photoelectron can be observed. This symmetry breaking is strongest for very small electron energies. Our experiment is consistent with a recent prediction by Serov and Kheifets [Phys. Rev. A 89, 031402 (2014)]. In their model, which treats the photoelectron classically, the symmetry breaking is induced by the retroaction of the long-range Coulomb potential onto the dissociating H_{2}^{+}.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.

Observation of a Neutral Structure near the DD[over ¯]^{*} Mass Threshold in e^{+}e^{-}→(DD[over ¯]^{*})^{0}π^{0} at sqrt[s]=4.226 and 4.257 GeV

A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)]  MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)]  MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)]  pb at 4.226 GeV and [47±9(stat)±10(syst)]  pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.

Measurement of the Absolute Branching Fraction for Λ_{c}^{+}→Λe^{+}ν_{e}

We report the first measurement of the absolute branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e}. This measurement is based on 567  pb^{-1} of e^{+}e^{-} annihilation data produced at sqrt[s]=4.599  GeV, which is just above the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be B(Λ_{c}^{+}→Λe^{+}ν_{e})=[3.63±0.38(stat)±0.20(syst)]%, representing a significant improvement in precision over the current indirect determination. As the branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e} is the benchmark for those of other Λ_{c}^{+} semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.

Comparison of iterated single-step and Bayesian regressions on genomic evaluations for age at 100 kg in swine

The effects of modified single-step genomic best linear unbiased prediction (ssGBLUP) iterations on GEBV and SNP were investigated using 85,388 age at 100 kg phenotypes from the BRF SA breeding program Landrace pure line animals, off-tested between 2002 and 2013. Pedigree data comprised animals born between 1999 and 2013. A total of 1,068 animals were assigned to the training population, in which all of them had genotypes, original and corrected age at 100 kg phenotypes, and weighted deregressed proof records. A total of 100 genotyped animals, with high accuracy age at 100 kg estimated breeding values, were assigned to the validation population. After applying the quality control workflow, a set of 41,042 SNP was used for the analysis. Standard and modified ssGBLUP, BayesCπ, and Bayesian Lasso were compared, and their predictive abilities were accessed by approximate true and GEBV correlations. Modified ssGBLUP iteration effects on SNP estimates and GEBV were relevant, in which assigned differential weights and shrinkage caused important losses on ssGBLUP predictive ability for age at 100 kg GEBV. Even though ssGBLUP accuracy can be equal or better than the compared Bayesian methods, additional gains can be obtained by correctly identifying the number of iterations required for best ssGBLUP performance.

Observation of a Neutral Charmoniumlike State Z_{c}(4025)^{0} in e^{+}e^{-}→(D^{*}D[over ¯]^{*})^{0}π^{0}

We report a study of the process e^{+}e^{-}→(D^{*}D[over ¯]^{*})^{0}π^{0} using e^{+}e^{-} collision data samples with integrated luminosities of 1092 pb^{-1} at sqrt[s]=4.23 GeV and 826 pb^{-1} at sqrt[s]=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the (D^{*}D[over ¯]^{*})^{0} mass threshold in the π^{0} recoil mass spectrum, which we denote as Z_{c}(4025)^{0}. Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be (4025.5_{-4.7}^{+2.0}±3.1) MeV/c^{2} and (23.0±6.0±1.0) MeV, respectively. The Born cross sections of e^{+}e^{-}→Z_{c}(4025)^{0}π^{0}→(D^{*}D[over ¯]^{*})^{0}π^{0} are measured to be (61.6±8.2±9.0) pb at sqrt[s]=4.23 GeV and (43.4±8.0±5.4) pb at sqrt[s]=4.26 GeV. The first uncertainties are statistical and the second are systematic.

Observation of Z_{c}(3900)^{0} in e^{+}e^{-}→π^{0}π^{0}J/ψ

Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Z_{c}(3900)^{0} with a significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2  MeV/c^{2} and 29.6±8.2±8.2  MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e^{+}e^{-}→π^{0}π^{0}J/ψ and the fraction of it attributable to π^{0}Z_{c}(3900)^{0}→π^{0}π^{0}J/ψ in the range E_{c.m.}=4.19-4.42  GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Z_{c}(3900)^{±}.

Cannabinoid type-1 receptor signaling in central serotonergic neurons regulates anxiety-like behavior and sociability

The endocannabinoid (eCB) system possesses neuromodulatory functions by influencing the release of various neurotransmitters, including γ-aminobutyric acid (GABA) and glutamate. A functional interaction between eCBs and the serotonergic system has already been suggested. Previously, we showed that cannabinoid type-1 (CB1) receptor mRNA and protein are localized in serotonergic neurons of the raphe nuclei, implying that the eCB system can modulate serotonergic functions. In order to substantiate the physiological role of the CB1 receptor in serotonergic neurons of the raphe nuclei, we generated serotonergic 5-hydroxytryptamine (5-HT) neuron-specific CB 1 receptor-deficient mice, using the Cre/loxP system with a tamoxifen-inducible Cre recombinase under the control of the regulatory sequences of the tryptophan hydroxylase 2 gene (TPH2-CreER (T2)), thus, restricting the recombination to 5-HT neurons of the central nervous system (CNS). Applying several different behavioral paradigms, we revealed that mice lacking the CB1 receptor in serotonergic neurons are more anxious and less sociable than control littermates. Thus, we were able to show that functional CB1 receptor signaling in central serotonergic neurons modulates distinct behaviors in mice.