First CLAS12 Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries in the Extended Valence Region.

Deeply virtual Compton scattering (DVCS) allows one to probe generalized parton distributions describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarized protons. The results greatly extend the Q^{2} and Bjorken-x phase space beyond the existing data in the valence region and provide 1600 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies.

Observation of Correlations between Spin and Transverse Momenta in Back-to-Back Dihadron Production at CLAS12.

We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction in the deep inelastic scattering process. In this reaction, two hadrons are produced in opposite hemispheres along the z axis in the virtual photon-target nucleon center-of-mass frame, with the first hadron produced in the current-fragmentation region and the second in the target-fragmentation region. The data were taken with longitudinally polarized electron beams of 10.2 and 10.6 GeV incident on an unpolarized liquid-hydrogen target using the CLAS12 spectrometer at Jefferson Lab. Observed nonzero sinΔϕ modulations in ep→e^{'}pπ^{+}X events, where Δϕ is the difference of the azimuthal angles of the proton and pion in the virtual photon and target nucleon center-of-mass frame, indicate that correlations between the spin and transverse momenta of hadrons produced in the target- and current-fragmentation regions may be significant. The measured beam-spin asymmetries provide a first access in dihadron production to a previously unexplored leading-twist spin- and transverse-momentum-dependent fracture function. The fracture functions describe the hadronization of the target remnant after the hard scattering of a virtual photon off a quark in the target particle and provide a new avenue for studying nucleonic structure and hadronization.

First Measurement of Λ Electroproduction off Nuclei in the Current and Target Fragmentation Regions.

We report results of Λ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014 GeV electron beam. These results represent the first measurements of the Λ multiplicity ratio and transverse momentum broadening as a function of the energy fraction (z) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high z and an enhancement at low z. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high z. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons.

Long-term trajectories of bone metabolism parameters and bone mineral density (BMD) in obese patients treated with metabolic surgery: a real-world, retrospective study.

PURPOSE: Potential negative effects of metabolic surgery on skeletal integrity remain a concern, since long-term data of different surgical approaches are poor. This study aimed to describe changes in bone metabolism in subjects with obesity undergoing both Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). METHODS: A single center, retrospective, observational clinical study on real-world data was performed enrolling subjects undergoing metabolic surgery. RESULTS: 123 subjects were enrolled (males 31: females 92; ages 48.2 ± 7.9 years). All patients were evaluated until 16.9 ± 8.1 months after surgery, while a small group was evaluated up to 4.5 years. All patients were treated after surgery with calcium and vitamin D integration. Both calcium and phosphate serum levels significantly increased after metabolic surgery and remained stable during follow-up. These trends did not differ between RYGB and SG (p = 0.245). Ca/P ratio decreased after surgery compared to baseline (p < 0.001) and this decrease remained among follow-up visits. While 24-h urinary calcium remained stable across all visits, 24-h urinary phosphate showed lower levels after surgery (p = 0.014), also according to surgery technique. Parathyroid hormone decreased (p < 0.001) and both vitamin D (p < 0.001) and C-terminal telopeptide of type I collagen (p = 0.001) increased after surgery. CONCLUSION: We demonstrated that calcium and phosphorous metabolism shows slight modification even after several years since metabolic surgery, irrespective of calcium and vitamin D supplementation. This different set point is characterized by a phosphate serum levels increase, together with a persistent bone loss, suggesting that supplementation alone may not ensure the maintenance of bone health in these patients.

Multidimensional, High Precision Measurements of Beam Single Spin Asymmetries in Semi-inclusive π

High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single π^{+} SIDIS data over a large kinematic range in Bjorken x, fractional energy, and transverse momentum of the hadron as well as photon virtualities Q^{2} ranging from 1-7 GeV^{2}. In particular, the structure function ratio F_{LU}^{sinϕ}/F_{UU} has been determined, where F_{LU}^{sinϕ} is a twist-3 quantity that can reveal novel aspects of emergent hadron mass and quark-gluon correlations within the nucleon. The data's impact on the evolving understanding of the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing transverse momentum dependent parton distribution functions.

Observation of Azimuth-Dependent Suppression of Hadron Pairs in Electron Scattering off Nuclei.

We present the first measurement of dihadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the gibuu model, which suggests that hadrons form near the nuclear surface and undergo multiple scattering in nuclei.These results show that angular correlation studies can open a new way to elucidate how hadrons form and interact inside nuclei.

Improved Λp Elastic Scattering Cross Sections between 0.9 and 2.0 GeV/c as a Main Ingredient of the Neutron Star Equation of State.

Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state. Yet, compared to other elastic scattering processes, there is very little data on Λ-N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the Λp→Λp elastic scattering cross section in the incident Λ momentum range 0.9-2.0 GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments.

First Measurement of Timelike Compton Scattering.

We present the first measurement of the timelike Compton scattering process, γp→p^{'}γ^{*}(γ^{*}→e^{+}e^{-}), obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities 2.25

Observation of Beam Spin Asymmetries in the Process ep→e

The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function G_{1}^{⊥}. A clear sign change is observed around the ρ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark.

Photoproduction of the f_{2}(1270) Meson Using the CLAS Detector.

The quark structure of the f_{2}(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq[over ¯]) resonance with quantum numbers J^{PC}=2^{++}. Recently, it was proposed that the f_{2}(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρ→π^{+}π^{-}, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γp→π^{0}π^{0}p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f_{2}(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.

Novel Way to Search for Light Dark Matter in Lepton Beam-Dump Experiments.

A novel mechanism to produce and detect light dark matter in experiments making use of GeV electrons (and positrons) impinging on a thick target (beam dump) is proposed. The positron-rich environment produced by the electromagnetic shower allows us to produce an A^{'} via nonresonant (e^{+}+e^{-}→γ+A^{'}) and resonant (e^{+}+e^{-}→A^{'}) annihilation on atomic electrons. The latter mechanism, for some selected kinematics, results in a larger sensitivity with respect to limits derived by the commonly used A^{'}-strahlung. This idea, applied to beam-dump experiments and active beam-dump experiments, pushes down the current limits by an order of magnitude.

Investigation of the

This Letter reports a study of the highly debated ^{10}Li structure through the d(^{9}Li,p)^{10}Li one-neutron transfer reaction at 100 MeV. The ^{10}Li energy spectrum is measured up to 4.6 MeV and angular distributions corresponding to different excitation energy regions are reported for the first time. The comparison between data and theoretical predictions, including pairing correlation effects, shows the existence of a p_{1/2} resonance at 0.45±0.03 MeV excitation energy, while no evidence for a significant s-wave contribution close to the threshold energy is observed. Moreover, two high-lying structures are populated at 1.5 and 2.9 MeV. The corresponding angular distributions suggest a significant s_{1/2} partial-wave contribution for the 1.5 MeV structure and a mixing of configurations at higher energy, with the d_{5/2} partial-wave contributing the most to the cross section.

Dimerisation increases the immunogenicity of recombinant Parj1/Parj2 allergens.

Purified recombinant Parj1 and Parj2 allergens bind an IgE repertoire common to the Parietaria species, allowing their use as marker molecules for diagnosis and therapy of allergic disease induced by the Urticaceae family. Preclinical studies on the in vivo immunogenicity of recombinant Parj1, Parj2 and their isoforms indicated differential capacity to induce IgG1 antibody responses, as indication of potential clinical use. A recombinant hetero-dimeric hybrid derivative (PjED), encompassing the shorter Parj1 isoform (Parj1.0201) and Parj2 allergen, was characterised. In vivo immunisation with PjED induces IgG1 antibodies capable of binding all the isoforms of Parietaria major allergens, overcoming the poor immunogenicity of single monomeric allergens. This feature makes PjED a promising candidate molecule to be further characterised for clinical applications in the treatment of Parietaria allergy.

Characterization of a Par j 1/Par j 2 mutant hybrid with reduced allergenicity for immunotherapy of Parietaria allergy.

BACKGROUND: Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens. METHODS: We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical-physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization. RESULTS: The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies. CONCLUSION: Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis.

Immuno-like assays and biomimetic microchips.

Biomimetic assays with molecularly imprinted polymers (MIPs) are bound to be an alternative to the traditional immuno-analytical methods based on antibodies. This is due to the unique combination of advantages displayed by the artificial materials including the absence of animal inoculation and sacrifice, unnecessary hapten conjugation to a carrier protein for stimulated production, the possibility of manufacturing MIPs against toxic substances, excellent physicochemical stability, reusability, ease of storage, and recognition in organic media. If the selectivity and affinity of MIPs are increased, many more immuno-like assays will be developed using radioactive, enzymatic, colorimetric, fluorescent, chemiluminescent, or electrochemical interrogation methods. This chapter provides a comprehensive comparison between the bio- and biomimetic entities and their usage.

D-KEFS trail making test as an embedded performance validity measure.

OBJECTIVE: The Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT) is a commonly used measure of processing speed and executive functioning that may also be useful as an embedded performance validity test (PVT). We evaluated the utility of several multi-condition indices on the D-KEFS TMT in three independent samples to determine an optimal multi-condition index and cutoff on the D-KEFS TMT. METHOD: Classification accuracy statistics for multiple multi-condition indices on the D-KEFS TMT were evaluated in three independent samples, including a sample with history of mild traumatic brain injury (TBI; n = 267) classified into psychometrically defined performance-valid and performance-invalid subgroups, the D-KEFS national normative sample (n = 1713), and a sample of middle- and older-aged adults diagnosed with mild cognitive impairment (MCI; n = 70). RESULTS: The D-KEFS TMT Conditions 1-5 summation index maximized sensitivity at .31 while maintaining adequate specificity at ≥.9. This index also had acceptable classification accuracy in both the D-KEFS national normative and MCI cross-validation samples, with the exception of the oldest subgroup of the national norming sample (i.e., individuals' ages 80-89), in which the observed failure rates for all multi-condition indices tested were greater than 10%. CONCLUSION: Our study provides support for the use the D-KEFS TMT Conditions 1-5 summation index as an embedded PVT among individuals younger than 80 years-old and from a range of conditions spanning from cognitively normal to mildly impaired; however, further validation is necessary.

A large population of galaxies 9 to 12 billion years back in the history of the Universe.

To understand the evolution of galaxies, we need to know as accurately as possible how many galaxies were present in the Universe at different epochs. Galaxies in the young Universe have hitherto mainly been identified using their expected optical colours, but this leaves open the possibility that a significant population remains undetected because their colours are the result of a complex mix of stars, gas, dust or active galactic nuclei. Here we report the results of a flux-limited I-band survey of galaxies at look-back times of 9 to 12 billion years. We find 970 galaxies with spectroscopic redshifts between 1.4 and 5. This population is 1.6 to 6.2 times larger than previous estimates, with the difference increasing towards brighter magnitudes. Strong ultraviolet continua (in the rest frame of the galaxies) indicate vigorous star formation rates of more than 10-100 solar masses per year. As a consequence, the cosmic star formation rate representing the volume-averaged production of stars is higher than previously measured at redshifts of 3 to 4.

Ecological behaviour of three serogroups of Legionella pneumophila within a model plumbing system.

Three Legionella pneumophila strains isolated from water samples and belonging to serogroups (sgs) 1, 6 and 9 were analysed for their capacity to colonise an experimental model simulating a domestic hot water distribution system. Ecological factors that could influence the persistence of the sgs such as intracellular life within protozoan hosts and bacterial interference by the production of antagonistic compounds were also studied. Viable counts of L. pneumophila increased both in the planktonic and in the sessile phases. Sg 6 showed a marked prevalence during the whole experiment and exhibited the highest host infection efficiency. Sg 1 was significantly less represented, but showed the highest capacity to reproduce in the protozoan hosts. Sg 9 was poorly represented and less adapted to intracellular life. Among the 14 bacteria constantly isolated in the system, five (35.7%) produced antagonistic substances against Legionella, with differences according to the bacterial strain and L. pneumophila sgs.

Multiresidue determination of fluoroquinolone antimicrobials in baby foods by liquid chromatography.

According to the current EU legislation, the presence of antimicrobial residues in baby foods is forbidden. Nevertheless, there is a lack of analytical methods to determine veterinary antimicrobials in baby foods and support the zero tolerance policy for this type of foods. This paper describes a simple method based on molecularly imprinted solid phase extraction (MISPE) and liquid chromatography with fluorescence detection (LC-FLD) for the determination of residues of fluoroquinolones (FQs) in baby foods. The method involves sample extraction with a solution of o-phosphoric acid (50mM, pH 3.0)/ACN (20:80, v/v) and further clean-up by loading the extracts onto MIP cartridges. Optimum MISPE conditions led to recoveries of the target FQs in the range of 92-106%, with RSDs <8%. Method validation has been performed according to Commission Decision 2002/657/EC, in terms of linearity, accuracy, precision, selectivity, decision limit (CCα) and detection capability (CCß). The proposed method has been successfully applied to the analysis of baby foods of different compositions bought in local supermarkets and pharmacies. The results did not show the presence of residual amounts of FQs in the analysed samples above the method's decision limits (CCα between 5 and 151µgkg(-1)).

The use of articulated external fixation for complex elbow trauma treatment.

INTRODUCTION: We use external elbow joint fixator (FE-F4) for fracture and dislocation of the ulnohumeral joint to evaluate the early articular mobilization maintaining concentric reduction, protecting the osteoligamentous reconstruction and avoiding postoperative stiffness. MATERIALS AND METHODS: Thirty-two patients (13 men and 19 women) were treated with FE-F4: 7 simple dislocations (21.9%), 15 distal humerus fractures (46.9%), 4 fractures and dislocations of which 1 terrible triad (12.5%), and 6 complex dislocations (18.7%). The mean age was 64 years. The average follow-up (FU) was 47 months. We evaluated the flexion-extension and prone-supination movement arc, VAS (Visual Analogue Scale), Quick DASH (Disability of the Arm, Shoulder and Hand score), MEPI (Mayo Elbow Performance Index) and the Broberg and Morrey rating system. RESULTS: The average ROM was 125.9° for flexion-extension, 77.8° for pronation and 79.7° for supination. The average VAS was 0.56 at the FU, the MEPI score of 93.6, the Broberg and Morrey rating system of 92.4 and the Quick DASH of 8.7. No major complications were found after surgery, and no objective or subjective posterolateral or medial joint instability was found. No patients at the FU had a new surgery with arthromyolysis or elbow arthroplasty. DISCUSSION: The elbow joint stiffness is the main cause of functional inability for the patient suffering from posttraumatic outcomes. The FE-F4 allows an early mobilization, even in case of injuries or complex reconstructions, keeping the joint stable and protecting any bone synthesis and the damaged capsule-ligament structures. LEVELS OF EVIDENCE: IV.