High speed simulation of flexible multibody dynamics

A multiflexible body dynamics code intended for fast turnaround control design trades is described. Nonlinear rigid body dynamics and linearized flexible dynamics combine to provide efficient solution of the equations of motion. Comparison with results from the DISCOS code provide verification of accuracy

Bilingual problem-solving training for caregivers of adults with dementia: A randomized, factorial-design protocol for the CaDeS trial

Objective: Caregivers of individuals with Alzheimer\u27s disease and related dementias (ADRD) often experience debilitating caregiver burden and emotional distress. To address these negative emotional consequences of caregiving, we will test and refine a strategy training intervention - Problem-Solving Training (PST) - that promotes self-efficacy and reduces caregiver burden and depressive symptoms. Previous research supports efficacy of PST; however, we do not know exactly how many PST sessions are needed or if post-training boosters are required to maintain PST benefits. Additionally, we translated and culturally-adapted PST into Descubriendo Soluciones Juntos (DSJ), our novel intervention for Spanish-speaking caregivers. Method: In this 2 × 2 factorial design randomized controlled trial, we will test remotely-delivered PST/DSJ sessions for both English- and Spanish-speaking caregivers of persons with ADRD to determine the optimal number of PST/DSJ sessions and ongoing booster sessions needed to best help caregivers navigate their current and future needs. Aims: 1) Compare the efficacy of three vs. six PST/DSJ sessions each with and without booster sessions for decreasing caregiver burden and depression and enhancing caregiver problem-solving; 2) Identify key factors associated with efficacy of PST/DSJ, including age, gender, primary language, relationship to care recipient, and uptake of the PST/DSJ strategy. Results: These results will establish guidelines needed for an evidence-based, culturally-adapted, and implementable problem-solving intervention to reduce caregiver stress and burden and improve caregiver health and well-being. Conclusion: This work promotes inclusion of diverse and underserved populations and advances therapeutic behavioral interventions that improve the lives of caregivers of individuals with chronic conditions

The ethics of using transgenic non-human primates to study what makes us human

An ongoing flood of comparative genomic data is identifying human lineage specific (HLS) sequences of unknown function, and there is strong interest in investigating their functional effects. Transgenic apes, our closest evolutionary relative, have the highest potential to express HLS sequences as they are expressed in Homo sapiens and likewise experience harm from such transgenic research. These harms render the conduct of this research ethically unacceptable in apes, justifying regulatory barriers between these species and all other non-human primates for transgenic research

What Research Ethics Should Learn from Genomics and Society Research: Lessons from the ELSI Congress of 2011

Research on the ethical, legal, and social implications (ELSI) of human genomics has devoted significant attention to the research ethics issues that arise from genomic science as it moves through the translational process. Given the prominence of these issues in today's debates over the state of research ethics overall, these studies are well positioned to contribute important data, contextual considerations, and policy arguments to the wider research ethics community's deliberations, and ultimately to develop a research ethics that can help guide biomedicine's future. In this essay, we illustrate this thesis through an analytic summary of the research presented at the 2011 ELSI Congress, an international meeting of genomics and society researchers. We identify three pivotal factors currently shaping genomic research, its clinical translation, and its societal implications: (1) the increasingly blurred boundary between research and treatment; (2) uncertainty — that is, the indefinite, indeterminate, and incomplete nature of much genomic information and the challenges that arise from making meaning and use of it; and (3) the role of negotiations between multiple scientific and non-scientific stakeholders in setting the priorities for and direction of biomedical research, as it is increasingly conducted “in the public square.

Measurement of the Deuteron Structure Function F₂ in the Resonance Region and Evaluation of its Moments

Inclusive electron scattering off the deuteron has been measured to extract the deuteron structure function F2 with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. The measurement covers the entire resonance region from the quasielastic peak up to the invariant mass of the final-state hadronic system W similar or equal to 2.7 GeV with four-momentum transfers Q2 from 0.4 to 6 (GeV/c)2. These data are complementary to previous measurements of the proton structure function F2 and cover a similar two-dimensional region of Q2 and Bjorken variable x. Determination of the deuteron F2 over a large x interval including the quasielastic peak as a function of Q2, together with the other world data, permit a direct evaluation of the structure function moments for the first time. By fitting the Q2 evolution of these moments with an OPE-based twist expansion we have obtained a separation of the leading twist and higher twist terms. The observed Q2 behavior of the higher twist contribution suggests a partial cancelation of different higher twists entering into the expansion with opposite signs. This cancelation, found also in the proton moments, is a manifestation of the duality phenomenon in the F2 structure function

Differential Cross Sections for + p → K⁺ + Y for Λ and Σ⁰ Hyperons

High-statistics cross sections for the reactions + p → K⁺ + Λ and + p → K⁺ + Σ⁰ have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 \u3c cos θ Kc.m. \u3c +0.95. In the K⁺ + Λ channel we confirm a resonance-like structure near W=1.9 GeV at backward kaon angles. The position and width of this structure change with angle, indicating that more than one resonance is likely playing a role. The K⁺ + Λ channel at forward angles and all energies is well described by a t-channel scaling characteristic of Regge exchange, whereas the same scaling applied to the K⁺ + Σ⁰ channel is less successful. Several existing theoretical models are compared to the data, but none provide a good representation of the results

Measurement of Deeply Virtual Compton Scattering Beam-Spin Asymmetries

The beam-spin asymmetries in the hard exclusive electroproduction of photons on the proton (→ep→epγ ) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (xB from 0.11 to 0.58, Q2 from 1 to 4.8  GeV2, −t from 0.09 to 1.8  GeV2), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A ≃ asinϕ/(1+ccosϕ). This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector

η’ Photoproduction on the Proton for Photon Energies from 1.527 to 2.227 GeV

Differential cross sections for the reaction γp→η′p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data suggest for the first time the coupling of the η′N channel to both the S11(1535) and P11(1710) resonances, known to couple strongly to the ηN channel in photoproduction on the proton, and the importance of J=3/2 resonances in the process

Prospects for Pentaquark Production at Meson Factories

Following Rosner [hep-ph/0312269], we consider B-decay production channels for the exotic I=0 and $I=3/2$ pentaquarks that have been recently reported. We also discuss new search channels for isovector pentaquarks, such as the $\Theta^{*++} (\bar s duuu)$, that are generically present in chiral soliton models but were not observed in recent experiments. Futhermore, we argue that weak decays of charmed baryons, such as the $\Lambda_c^+$ and $\Xi_c^0$, provide another clean way of detecting exotic baryons made of light quarks only. We also discuss discovery channels for charmed pentaquarks, such as the isosinglet $\Theta_c^0 (\bar c udud)$, in weak decays of bottom mesons and baryons. Finally, we discuss prospects for inclusive production of pentaquarks in $e^+ e^-$ collisions, with associated production of particles carrying the opposite baryon number.Comment: 15 pages, LaTeX; v2,v3: minor corrections, references added; v4: minor modifications, the version published in Physics Letters