Neutrino-Induced Coherent π^{+} Production in C, CH, Fe, and Pb at ⟨E_{ν}⟩∼6 GeV

MINERvA has measured the ν_{μ}-induced coherent π^{+} cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe), and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV ν_{μ} energies and at produced π^{+} energies and angles, E_{π}>1  GeV and θ_{π}<10°. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective A scaling to increase from an approximate A^{1/3} scaling at few GeV to an A^{2/3} scaling for E_{ν}>10  GeV.

Simultaneous Measurement of Muon Neutrino ν_{μ} Charged-Current Single π^{+} Production in CH, C, H_{2}O, Fe, and Pb Targets in MINERvA

Neutrino-induced charged-current single π^{+} production in the Δ(1232) resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this Letter, high statistic differential cross sections are reported for the semiexclusive reaction ν_{μ}A→μ^{-}π^{+}+ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wideband ν_{μ} beam with ⟨E_{ν}⟩≈6  GeV. Suppression of the cross section at low Q^{2} and enhancement of low T_{π} are observed in both light and heavy nuclear targets compared with phenomenological models used in current neutrino interaction generators. The cross sections per nucleon for iron and lead compared with CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

Simultaneous Measurement of ν_{μ} Quasielasticlike Cross Sections on CH, C, H_{2}O, Fe, and Pb as a Function of Muon Kinematics at MINERvA

This Letter presents the first simultaneous measurement of the quasielasticlike neutrino-nucleus cross sections on C, water, Fe, Pb, and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5  GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielasticlike interactions, which are major contributors to long-baseline neutrino oscillation data samples.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Simultaneous Measurement of Proton and Lepton Kinematics in Quasielasticlike ν_{μ}-Hydrocarbon Interactions from 2 to 20 GeV

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{μ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20  GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

High-Statistics Measurement of Neutrino Quasielasticlike Scattering at 6 GeV on a Hydrocarbon Target

We measure neutrino charged-current quasielasticlike scattering on hydrocarbon at high statistics using the wideband Neutrinos at the Main Injector beam with neutrino energy peaked at 6 GeV. The double-differential cross section is reported in terms of muon longitudinal (p_{∥}) and transverse (p_{⊥}) momentum. Cross section contours versus lepton momentum components are approximately described by a conventional generator-based simulation, however, discrepancies are observed for transverse momenta above 0.5  GeV/c for longitudinal momentum ranges 3-5 and 9-20  GeV/c. The single differential cross section versus momentum transfer squared (dσ/dQ_{QE}^{2}) is measured over a four-decade range of Q^{2} that extends to 10  GeV^{2}. The cross section turnover and falloff in the Q^{2} range 0.3-10  GeV^{2} is not fully reproduced by generator predictions that rely on dipole form factors. Our measurement probes the axial-vector content of the hadronic current and complements the electromagnetic form factor data obtained using electron-nucleon elastic scattering. These results help oscillation experiments because they probe the importance of various correlations and final-state interaction effects within the nucleus, which have different effects on the visible energy in detectors.

2419Reparative macrophage transplantation for myocardial repair: a refinement of bone marrow mononuclear cell-based therapy

Background

Recent research has revealed that reparative (alternatively activated or M2-like) macrophages play an important role in post-myocardial infarction (MI) cardiac repair, proposing that augmentation of these cells will enhance recovery from MI. Transplantation of bone marrow mononuclear cells (BM-MNCs) is an emerging therapy for MI while its therapeutic efficacy in previous clinical trials is not satisfactory. Given that BM-MNCs are a natural source of macrophages, we hypothesized that induced differentiation/polarisation of BM-MNCs to reparative macrophages before transplantation may enhance the effect of BM-MNC transplantation.

Purpose

This study aimed to develop a robust in vitro protocol to produce reparative macrophages from BM-MNCs and to establish the pre-clinical proof of concept data for reparative macrophage transplantation for the treatment of MI.

Methods and results

Mouse BM-MNCs were treated with M-CSF plus IL-4, IL-10, TGF-β1 or combinations of these in vitro. The concomitant M-CSF+IL-4 protocol (both 20ng/ml) produced the highest rate (89.7±0.7%) and number (1.7-fold larger than the original cell number) of CD11b+F4/80+CD206+ macrophages. Expression and secretion of tissue repair-related factors of the produced cells, including IGF-1, TGF-β1, VEGF and IL1-ra, were more extensive compared to BM-MNCs. Then, 5x105 BM-MNC-derived reparative macrophages, 5x105 BM-MNCs, or saline only (control) were intramyocardially injected in a mouse MI model based on coronary artery ligation. At 4 weeks after treatment, echocardiography demonstrated that reparative macrophage transplantation markedly improved cardiac function (left ventricular ejection fraction; 57.2±1.6%, n=11) compared to both BM-MNC transplantation (48.4±1.3%, n=9) and control group (44.4±2.0%, n=9). Histological studies showed that infarct size was the smallest after reparative macrophage transplantation in association with the greatest tissue repair in the peri-infarct myocardium, including augmented microvascular formation, reduced cardiomyocyte hypertrophy and reduced pathological interstitial fibrosis. These were corresponded to amplified myocardial upregulation of tissue repair-related genes. Of note, survival of donor reparative macrophages in the heart post-transplantation was >10-fold greater compared to BM-MNCs. It was also found that reparative macrophage transplantation increased host-derived cardiac reparative macrophages. This might be a part of the mechanism by which reparative macrophage transplantation augmented myocardial repair, and our in vitro antibody neutralisation study indicated that TGF-β1 played a role in this donor macrophage-to-host macrophage pathway.

Conclusion

M-CSF+IL-4 treatment was effective in producing reparative macrophages from BM-MNCs in vitro. Addition of this pre-treatment improved the therapeutic effect of BM-MNC transplantation. Further pre-clinical and clinical development of this advanced cell therapy is warrantied.

Acknowledgement/Funding

British Heart Foundation (RG/15/3/31236); Heart Research UK (RG2618/12/13 and TRP06/15); St Barts Medical School London

P2569Self-adhesive bi-layered dressing incorporating amnion-derived mesenchymal stromal cells for the treatment of heart failure: a pre-clinical proof of concept study

Introduction

Mesenchymal stromal cell (MSC) transplantation is a promising treatment to promote myocardial repair. Among various sources, the amnion has an advantage in mass production of high-quality MSCs due to its large initial cell-yield and prenatal nature of isolated cells. In addition to the powerful tissue-repair potential, amnion-derived MSCs (AMSCs) exhibit a robust immunomodulative ability, enabling allogeneic transplantation without immunosuppressive reagents. We here report a novel bioengineering technique to deliver AMSCs for myocardial repair by epicardial placement of self-adhesive, bi-layered, AMSC-incorporating dressings (AMSC-dressing), which is fabricable on-site (Figure A).

Methods and results

AMSC-dressing was fabricated by spreading AMSC suspension on the inner layer of a fibrin sealant film, composed of fibrinogen and thrombin. Due to the resulting adhesive AMSC-fibrin complex, the AMSC-dressing firmly adhered to the heart surface without the need for suture or additional glue. The outer collagen layer of the film facilitated the easy handling and also protected the AMSC-fibrin complex from external damage. We applied a 1 cm2 dressing containing 0, 1, 2 or 4 millions of rat AMSCs to a rat ischemic cardiomyopathy model (4 weeks post coronary artery ligation). Intramyocardial (IM) injection of 4 millions of AMSCs and sham treatment were also conducted. Echocardiography and catheterization consistently demonstrated that AMSC-dressing therapy improved cardiac function and reduced heart dilatation in a dose-dependent manner compared to the sham control. Furthermore, this therapeutic effect exceeded that of IM injection (Figure B). Histological analyses revealed that AMSC-dressing therapy resulted in augmented myocardial tissue repair (increased neovascularization, attenuated pathological fibrosis and reduced cardiomyocyte hypertrophy) compared to IM injection and sham groups. These effects were associated with increased upregulation of a range of tissue repair-related genes including Il10, Cxcl12, Igf1, Timp1, Hif1a, Tgfb, Mmp2, Hgf, Fgf2 and Vegf. Of note, it was elucidated that both initial retention and subsequent survival of donor AMSCs were enhanced by the dressing technique compared to IM injection. In addition, in vitro studies demonstrated that culturing in a fibrin glue not only enhanced upregulation of tissue-repair genes of AMSCs but also improved their survival against environmental stress through activating the Akt/PI3K cell-survival pathway.

Conclusion

AMSC-dressing therapy enhanced both quantity and quality of donor cell engraftment, leading to the augmented therapeutic efficacy, compared to the current method. Furthermore, this technique is user-friendly and requires no specialized equipment at the treating hospital, highlighting its great potential to be a widely-adopted, standard treatment for heart failure. Further development of this advanced cell therapy towards clinical application is justified.

Acknowledgement/Funding

British Heart Foundation, Heart Research UK, Japan Agency for Medical Research and Development, Kaneka Corporation

C-35 Clinical Diagnosis of Behavioral Variant Frontotemporal Dementia with Underlying Primary Age-Related Tauopathy

Objective

Primary age-related tauopathy (PART) is a neuropathologic entity characterized by neurofibrillary tangles in medial temporal regions comparable to Alzheimer’s disease (AD), but with few or no amyloid plaques. A definitive clinical phenotype for PART has not been determined. Some studies report milder deficits and a longer course compared with AD. In the National Alzheimer’s Coordinating Center database, the most common clinical diagnosis of PART cases classified as dementia is AD, though primary progressive aphasia/behavioral-variant frontotemporal dementia (bvFTD) is also common. We describe 3 patients diagnosed with bvFTD later found to have PART to further describe possible PART phenotypes.

Method

Charts of 3 autopsy-proven PART cases clinically diagnosed as bvFTD by consensus conference were reviewed. All patients (A, B, C) were male and presented with behavioral changes. Only B was APOE4+. Neuroimaging was mostly unremarkable (ventriculomegaly in patient C).

Results

All subjects presented with anosognosia, fatigue, and behavioral changes, 1 (A) with pronounced apathy and 2 (B, C) with disinhibition, impulsivity, and mood swings. Onset was early 70’s for A & C, and 50’s for B. Patients B & C had gradual onset/course (~20 years) with initial subtle executive (EF) dysfunction and intact memory. Patient A had a 6-year course and initial deficits in EF and memory.

Conclusion

This review underscores the varied presentation and clinical course of PART, including presence of early behavioral changes. Slower progression as previously reported was seen in 2 of 3 patients. Future research is warranted to better characterize the entire spectrum of clinical presentations in subjects with PART neuropathology.

Publisher's Note: Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer [Phys. Rev. Lett. 116, 071802 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.116.071802.

Measurement of Final-State Correlations in Neutrino Muon-Proton Mesonless Production on Hydrocarbon at ⟨E_{ν}⟩=3 GeV

Final-state kinematic imbalances are measured in mesonless production of ν_{μ}+A→μ^{-}+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ^{-}-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

We report on multinucleon effects in low momentum transfer (<0.8  GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

Charged-current ν_{μ} interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q^{2}, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q^{2} and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

Measurement of Neutral-Current K^{+} Production by Neutrinos using MINERvA

Neutral-current production of K^{+} by atmospheric neutrinos is a background in searches for the proton decay p→K^{+}ν[over ¯]. Reactions such as νp→νK^{+}Λ are indistinguishable from proton decays when the decay products of the Λ are below detection threshold. Events with K^{+} are identified in MINERvA by reconstructing the timing signature of a K^{+} decay at rest. A sample of 201 neutrino-induced neutral-current K^{+} events is used to measure differential cross sections with respect to the K^{+} kinetic energy, and the non-K^{+} hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from π^{0} decay, which would veto a neutral-current K^{+} event in a proton decay search, is performed, and a 2σ deficit of detached photons is observed relative to the genie prediction.

Evidence for Neutral-Current Diffractive π^{0} Production from Hydrogen in Neutrino Interactions on Hydrocarbon

The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π^{0} production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26±0.02(stat.)±0.08(sys.)×10^{-39}  cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π^{0} production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ν_{μ} to ν_{e} oscillations.

Evidence of Coherent K^{+} Meson Production in Neutrino-Nucleus Scattering

Neutrino-induced charged-current coherent kaon production ν_{μ}A→μ^{-}K^{+}A is a rare, inelastic electroweak process that brings a K^{+} on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than the neutrino-induced charged-current coherent pion production because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K^{+}, μ^{-}, and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3σ significance.

Animal Models for Medication Development and Application to Treat Fetal Alcohol Effects

Ethanol consumption during pregnancy can have lifelong consequences for the offspring, their family and society. Fetal alcohol spectrum disorders (FASD) include a range of physical and behavioral effects with the most significant impact occurring as a result of the effects of ethanol on the developing central nervous system (CNS). To date, there are no FDA approved drugs that have been tested that prevent/reduce or specifically treat the symptoms of FASD. There are several promising lines of research from rodent models aimed at reducing the neurotoxic effects of ethanol on the developing CNS or in treating the resulting behavioral impairments but these have not yet moved to clinical testing. The current review discusses some of the most promising targets for intervention and provides a review of the past and ongoing efforts to develop and screen pharmacological treatments for reducing the effects of prenatal ethanol exposure.

Measurement of Electron Neutrino Quasielastic and Quasielasticlike Scattering on Hydrocarbon at ⟨E_{ν}⟩=3.6 GeV

The first direct measurement of electron neutrino quasielastic and quasielasticlike scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in the electron production angle, electron energy, and Q^{2} are presented. The ratio of the quasielastic, flux-integrated differential cross section in Q^{2} for ν_{e} with that of similarly selected ν_{μ}-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current ν_{e} interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well described by the predictions of the neutrino event generator GENIE.

Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ν_{μ} interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

Measurement of coherent production of π(±) in neutrino and antineutrino beams on carbon from Eν of 1.5 to 20 GeV

Neutrino-induced coherent charged pion production on nuclei νμA→μ(±)π(∓)A is a rare, inelastic interaction in which a small squared four-momentum |t| is transferred to the recoil nucleus, leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct |t| from the final-state pion and muon. We select low |t| events to isolate a sample rich in coherent candidates. By selecting low |t| events, we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and antineutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

Measurement of ratios of νμ charged-current cross sections on C, Fe, and Pb to CH at neutrino energies 2-20 GeV

We present measurements of ν(μ) charged-current cross section ratios on carbon, iron, and lead relative to a scintillator (CH) using the fine-grained MINERvA detector exposed to the NuMI neutrino beam at Fermilab. The measurements utilize events of energies 2<E(ν)<20 GeV, with ⟨E(ν)⟩ = 8 GeV, which have a reconstructed μ(-) scattering angle less than 17° to extract ratios of inclusive total cross sections as a function of neutrino energy E(ν) and flux-integrated differential cross sections with respect to the Bjorken scaling variable x. These results provide the first high-statistics direct measurements of nuclear effects in neutrino scattering using different targets in the same neutrino beam. Measured cross section ratios exhibit a relative depletion at low x and enhancement at large x. Both become more pronounced as the nucleon number of the target nucleus increases. The data are not reproduced by GENIE, a conventional neutrino-nucleus scattering simulation, or by the alternative models for the nuclear dependence of inelastic scattering that are considered.

Kidneys at higher risk of discard: expanding the role of dual kidney transplantation

Half of the recovered expanded criteria donor (ECD) kidneys are discarded in the United States. A new kidney allocation system offers kidneys at higher risk of discard, Kidney Donor Profile Index (KDPI)>85%, to a wider geographic area to promote broader sharing and expedite utilization. Dual kidney transplantation (DKT) based on the KDPI is a potential option to streamline allocation of kidneys which otherwise would have been discarded. To assess the clinical utility of the KDPI in kidneys at higher risk of discard, we analyzed the OPTN/UNOS Registry that included the deceased donor kidneys recovered between 2002 and 2012. The primary outcomes were allograft survival, patient survival and discard rate based on different KDPI categories (<80%, 80-90% and >90%). Kidneys with KDPI>90% were associated with increased odds of discard (OR=1.99, 95% CI 1.74-2.29) compared to ones with KDPI<80%. DKTs of KDPI>90% were associated with lower overall allograft failure (HR=0.74, 95% CI 0.62-0.89) and better patient survival (HR=0.79, 95% CI 0.64-0.98) compared to single ECD kidneys with KDPI>90%. Kidneys at higher risk of discard may be offered in the up-front allocation system as a DKT. Further modeling and simulation studies are required to determine a reasonable KDPI cutoff percentile.

Measurement of muon neutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

Measurement of muon antineutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.

Early and late introduction of probes and stimulus control acquisition in fading

College students learned to name Braille patterns presented visually using a fading procedure in which Braille patterns were superimposed on letter names after which letter names were attenuated. Measurement of acquisition was accomplished by presenting probes-consisting of the Braille stimuli only-throughout fading. Effects of probes upon acquisition were assessed by introducing probes early or late in fading. Fewer fading levels were needed for Braille elements to acquire control when probes were introduced early rather than late. When probes were introduced late, all subjects learned to name the Braille elements as the letters were being faded out. When probes were introduced early, however, most subjects learned to name the Braille elements as they were being faded in. Since virtually no errors occurred during compound-stimulus presentations, the probe procedure did not induce errors during acquisition. Quantitative analysis of probe data suggested that inclusion of probes enhanced the control acquired by the Braille elements during compound-stimulus presentations. The reported effects may have been due to differences in the relative frequency of reinforcement presented during compounds and probes.

Fading and errorless transfer in successive discriminations

A successive discrimination between red positive and green negative stimuli was established with pigeon subjects. Then, lines with different angular orientations were superimposed on one of the colors to form compound stimuli. Finally, either the colored element of the positive compound, the colored element of the negative compound, or both colored elements together, were gradually attenuated. Before each attenuation, the line elements were presented alone against dark backgrounds as probes to assess the degree to which they had acquired control of responding. When the positive color was attenuated alone or in conjunction with the negative color, angular orientation acquired control of responding in an errorless fashion. Lines, however, did not acquire control when only the negative component was attenuated. These results were interpreted in terms of changes in the predictability of reinforcement by color and line elements during stimulus attenuation. Finally, attenuation of the negative stimulus influenced the number of "dimensions" of the new line stimuli that acquired control of responding. When the positive stimulus was attenuated with the negative, only one dimension of the lines acquired control. When the positive stimulus was attenuated without the negative, however, more than one dimension of the lines acquired control of responding. These results were interpreted in terms of how errorless performance can be maintained while an organism attends to different dimensions of the new stimuli.

The structure of equivalence classes

THE STRUCTURE OF EQUIVALENCE CLASSES CAN BE COMPLETELY DESCRIBED BY FOUR PARAMETERS: class size, number of nodes, the distribution of "singles" among nodes, and directionality of training. Class size refers to the number of stimuli in a class. Nodes are stimuli linked by training to at least two other stimuli. Singles are stimuli linked by training to only one other stimulus. The distribution of singles refers to the number of singles linked by training to each node. Directionality of training refers to the use of stimuli as samples and as comparison stimuli in training. These four parameters define the different ways in which the stimuli in a class can be organized, and thus provide a basis for systematically characterizing the properties of stimuli in a given equivalence class. The four parameters can also be used to account for the development of individual differences that are commonly characterized in terms of "understanding" and connotative meaning.Methods are described for generating all possible combinations of parameter values, and a formula is introduced which specifies all of the parameter values for an equivalence class. Its utility for interrelating experimental procedures is demonstrated by analyzing a number of representative experiments that have addressed equivalence-class formation.

Stimulus equivalence and transitive associations: A methodological analysis

When a number of two-stimulus relations are established through training within a set of stimuli, other two-stimulus relations often emerge in the same set without direct training. These, termed "transitive stimulus relations," have been demonstrated with a variety of visual and auditory stimuli. The phenomenon has served as a behavioral model for explaining the emergence of rudimentary comprehension and reading skills, and the development of generative syntactic repertoires. This article considers the range of relations that can arise between a given number of stimuli in a class, the number of directly established two-stimulus relations necessary for the emergence of transitive relations, the forms that training sets of stimuli can take, and the number of transitive two-stimulus relations that can be induced without direct training. The procedures needed to establish and assess transitive stimulus control, the possible interactions between the training and testing procedures, and the constrainst these interactions place upon the analysis of transitive stimulus control are also examined. The present analysis indicates that in a transitivity test, choice among such stimuli may be controlled by (1) the relation between the sample and the positive comparison stimulus (transitive stimulus control), (2) the relation between the sample and the negative comparison stimulus (S- rule control), and (3) possible discriminative properties that may inadvertently be established in the positive and negative comparison stimuli (valence control). Methods are described for distinguishing these three forms of stimulus control.

Maintained nodal-distance effects in equivalence classes

Twelve subjects were trained to select one of two stimuli from a pair (the B pair) when presented with one of two stimuli from another pair (the A pair), thus establishing two AB relations, A1-B1 and A2-B2. In a similar fashion, additional stimuli were used to establish BC, CD, and DE relations. Trials used to train all relations occurred in each session. Once performances were established, probe trials were introduced that tested for the emergence of untrained relations (e.g., B1-D1 or A1-E1). These emergent relations were categorized according to nodal distance (i.e., the number of stimuli across which transitivity would have to hold in order for the relation to emerge). For example, a test for A2-C2 crosses one node (B2), whereas a test for A1-E1 crosses three nodes (B1, C1, and D1). Only 2 of the subjects formed equivalence classes. The evocation of class-appropriate responding by each emergent-relation probe was an inverse function of nodal distance for all 12 subjects. In addition, performance on the originally trained relations was disrupted by the introduction of probes. The 2 subjects who exhibited equivalence classes were then trained to make different numbers of key presses in the presence of each of the four A and E stimuli. In a response-transfer test, the B, C, and D stimuli evoked the responses trained to the A and E stimuli in the same equivalence class. Likelihood of class-appropriate responses was an inverse function of nodal distance, and this pattern persisted across testing. Reaction times in the transfer test were an inverted U-shaped function of nodal distance. Because training of the baseline relations occurred concurrently and the B, C, and D stimuli were presented an equal number of times before the transfer test, the test performances illustrate effects of nodal distance that were not confounded by order or amount of experience with the stimuli. The results imply that ordered, sequential exposure to individual stimulus relations may facilitate the development of equivalence classes and that the relatedness of stimuli within an equivalence class is a relatively permanent inverse function of nodal distance.

Response rate, latency, and resistance to change

Pigeons were trained on a multiple variable-interval/variable-interval schedule with pacing contingencies that generated high response rates in one component and low response rates in the other. Timeout periods separated the schedule components. During resistance-to-change tests, response-independent food was presented during the timeout periods, and the duration of that food presentation was varied among test sessions. Response rates in the schedule components decreased and latencies to the first response increased as a function of the duration of food presentations during the timeout. Both dependent measures changed about the same amount relative to their own baseline levels. The conclusions are that baseline response rates controlled by pacing contingencies are equally resistant to change, given equal reinforcement densities, and latency is a sensitive measure of resistance to change.

The stages of acquisition in stimulus fading

Pigeons were exposed to a stimulus fading procedure in which control of responding was transferred from red and black stimuli to lines of different angular orientation. After superimposing one line on the red stimulus and the other line on the black stimulus, the intensity of the lines was gradually increased and that of the red stimulus was gradually reduced. Probes consisting of red and line stimuli presented separately were used during the course of fading to assess control exerted by each element of the compound. As the lines were faded in, they did not acquire control of responding. As red was faded out, control of responding was acquired first by the lower intensity red stimuli in combination with the line stimulus, and finally by the angular orientation of the lines. Probes also determined the point at which the line stimuli, presented alone, would maintain a high degree of stimulus control. The results demonstrated that new stimuli in fading acquire dimensional control of responding in two sequential stages. Acquisition of stimulus control in fading was explained in terms of attenuation of stimulus blocking.

Observation of D+ --> etae + nue

Using a 281 pb-1 data sample collected at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D+ --> etae + nue. We also set upper limits for D+ --> eta'e + nue and D + --> varphie + nue that are about 2 orders of magnitude more restrictive than those obtained by previous experiments.

Observation of eta' decays to pi+pi-pi0 and pi+pi-e+e-

Using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector at the CESR e;{+}e;{-} collider, we make the first observations of the decays eta;{'}-->pi;{+}pi;{-}pi;{0} and eta;{'}-->pi;{+}pi;{-}e;{+}e;{-}, measuring absolute branching fractions (37_{-9};{+11}+/-4)x10;{-4} and (25_{-9};{+12}+/-5)x10;{-4}, respectively. For eta;{'}-->pi;{+}pi;{-}pi;{0}, this result probes the mechanism of isospin violation and the roles of pi;{0}/eta/eta;{'}-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for eta;{'} decays to pi;{+}pi;{-}micro;{+}micro;{-}, 2(pi;{+}pi;{-}), pi;{+}pi;{-}2pi;{0}, 2(pi;{+}pi;{-})pi;{0}, 3(pi;{+}pi;{-}), and invisible final states.

J/psi and psi(2S) Radiative Transitions to eta_{c}

Using 2.45x10;{7} psi(2S) decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)-->gammaeta_{c})=(4.32+/-0.16+/-0.60)x10;{-3}, B(J/psi-->gammaeta_{c})/B(psi(2S)-->gammaeta_{c})=4.59+/-0.23+/-0.64, and B(J/psi-->gammaeta_{c})=(1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_{c} line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_{c} mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_{c} mass in radiative transitions and other production mechanisms.