Distinct visual coding strategies mediate grasping and pantomime-grasping of 2D and 3D objects.

An issue of current debate in the visuomotor control literature surrounds whether 2D and 3D objects rely on similar or dissociable visual information in supporting goal-directed grasping. Accordingly, in Experiment One I had participants grasp 2D and 3D objects wherein just-noticeable-difference (JND) scores for aperture shaping were computed to determine the extent to which such actions adhere to the psychophysical principles of Weber’s law. Results demonstrated that JNDs scaled in accordance with Weber’s law in a time-independent and time-dependent manner for 2D and 3D grasping, respectively. In Experiment Two, I sought to further explore the cognitive demands of grasping by having participants pantomime the grasping of 2D and 3D objects. Results showed that grasping 2D objects and pantomime grasping elicited a common time-independent adherence to Weber’s law that is distinct from grasping a 3D object. Thus, results demonstrate that 2D and 3D grasping are mediated by distinct visual information

Polarization proximity effect in isolator crystal pairs

We experimentally studied the polarization dynamics (orientation and ellipticity) of near infrared light transmitted through magnetooptic Yttrium Iron Garnet crystal pairs using a modified balanced detection scheme. When the pair separation is in the sub-millimeter range, we observed a proximity effect in which the saturation field is reduced by up to 20%. 1D magnetostatic calculations suggest that the proximity effect originates from magnetostatic interactions between the dipole moments of the isolator crystals. This substantial reduction of the saturation field is potentially useful for the realization of low-power integrated magneto-optical devices.Comment: submitted to Optics Letter

Misdiagnosis, Mistreatment, and Harm - When Medical Care Ignores Social Forces.

The Case Studies in Social Medicine demonstrate that when physicians use only biologic or individual behavioral interventions to treat diseases that stem from or are exacerbated by social factors, we risk harming the patients we seek to serve

Quantum and classical chaos for a single trapped ion

In this paper we investigate the quantum and classical dynamics of a single trapped ion subject to nonlinear kicks derived from a periodic sequence of Guassian laser pulses. We show that the classical system exhibits diffusive growth in the energy, or 'heating', while quantum mechanics suppresses this heating. This system may be realized in current single trapped-ion experiments with the addition of near-field optics to introduce tightly focussed laser pulses into the trap.Comment: 8 pages, REVTEX, 8 figure

Autologous adoptive T-cell therapy for recurrent or drug-resistant cytomegalovirus complications in solid organ transplant patients: a single-arm open-label phase I clinical trial

BACKGROUND: Opportunistic infections including cytomegalovirus (CMV) are a major cause of morbidity and mortality in solid organ transplant (SOT) recipients. The recurrent and protracted use of anti-viral drugs with eventual emergence of drug resistance represents a significant constraint to therapy. While adoptive T-cell therapy has been successfully used in haematopoietic stem cell transplant recipients, its extension to the SOT setting poses a considerable challenge because of the inhibitory effects of immunosuppressive drugs on the virus-specific T-cell response in vivo, and the perceived risk of graft rejection. METHODS: In this prospective study, 22 SOT recipients (13 renal, 8 lung and 1 heart) with recurrent or ganciclovir-resistant CMV infection were recruited and of these, 13 patients were treated with in vitro-expanded autologous CMV-specific T cells. These patients were monitored for safety, clinical symptoms and immune reconstitution. RESULTS: Autologous CMV-specific T-cell manufacture was attempted for 21 patients, and was successful in 20 cases. The use of this adoptive immunotherapy was associated with no therapy-related serious adverse events. Eleven (84%) of the thirteen treated patients showed improvement in symptoms, including complete resolution or reduction in DNAemia, CMV-associated end organ disease and/or the cessation or reduced use of anti-viral drugs. Furthermore, many of these patients showed co-incident increased frequency of CMV-specific T cells in peripheral blood following completion of T-cell therapy. CONCLUSIONS: The data presented here demonstrate for the first time the clinical safety of CMV-specific adoptive T-cell therapy and its potential therapeutic benefit for SOT patients with recurrent and/or drug-resistant CMV infection or disease

Short Duration Waveforms Recorded Extracellularly from Freely Moving Rats are Representative of Axonal Activity

While extracellular somatic action potentials from freely moving rats have been well characterized, axonal activity has not. We report direct extracellular tetrode recordings of putative axons whose principal feature is a short duration waveform (SDW) with an average peak-trough length less than 179 μs. While SDW recordings using tetrodes have previously been treated as questionable or classified as cells, we hypothesize that they are representative of axonal activity. These waveforms have significantly shorter duration than somatic action potentials, are triphasic and are therefore similar to classic descriptions of microelectrode recordings in white matter and of in vitro action potential propagation along axons. We describe SDWs recorded from pure white-matter tracts including the alveus and corpus callosum. Recordings of several SDWs in the alveus exhibit grid-like firing patterns suggesting these axons carry spatial information from entorhinal cortical neurons. Finally, we locally injected the GABAA agonist Muscimol into layer CA1 of the hippocampus while simultaneously recording somatic activity and SDWs on the same tetrodes. The persistent activity of SDWs during Muscimol inactivation of somatic action potentials indicates that SDWs are representative of action potential propagation along axons projecting from more distal somata. This characterization is important as it illustrates the dangers of exclusively using spike duration as the sole determinant of unit type, particularly in the case of interneurons whose peak-trough times overlap with SDWs. It may also allow future studies to explore how axonal projections from disparate brain regions integrate spatial information in the hippocampus, and provide a basis for studying the effects of pharmaceutical agents on signal transmission in axons, and ultimately to aid in defining the potential role of axons in cognition

State-Dependent Differences in Functional Connectivity in Young Children With Autism Spectrum Disorder

AbstractBackgroundWhile there is increasing evidence of altered brain connectivity in autism, the degree and direction of these alterations in connectivity and their uniqueness to autism has not been established. The aim of the present study was to compare connectivity in children with autism to that of typically developing controls and children with developmental delay without autism.MethodsWe assessed EEG spectral power, coherence, phase lag, Pearson and partial correlations, and epileptiform activity during the awake, slow wave sleep, and REM sleep states in 137 children aged 2 to 6years with autism (n=87), developmental delay without autism (n=21), or typical development (n=29).FindingsWe found that brain connectivity, as measured by coherence, phase lag, and Pearson and partial correlations distinguished children with autism from both neurotypical and developmentally delayed children. In general, children with autism had increased coherence which was most prominent during slow wave sleep.InterpretationFunctional connectivity is distinctly different in children with autism compared to samples with typical development and developmental delay without autism. Differences in connectivity in autism are state and region related. In this study, children with autism were characterized by a dynamically evolving pattern of altered connectivity

Biological laterality and peripheral nerve DTI metrics

BACKGROUND AND PURPOSE: Clinical comparisons do not usually take laterality into account and thus may report erroneous or misleading data. The concept of laterality, well evaluated in brain and motor systems, may also apply at the level of peripheral nerves. Therefore, we sought to evaluate the extent to which we could observe an effect of laterality in MRI-collected white matter indices of the sciatic nerve and its two branches (tibial and fibular). MATERIALS AND METHODS: We enrolled 17 healthy persons and performed peripheral nerve diffusion weighted imaging (DWI) and magnetization transfer imaging (MTI) of the sciatic, tibial and fibular nerve. Participants were scanned bilaterally, and findings were divided into ipsilateral and contralateral nerve fibers relative to self-reporting of hand dominance. Generalized estimating equation modeling was used to evaluate nerve fiber differences between ipsilateral and contralateral legs while controlling for confounding variables. All findings controlled for age, sex and number of scans performed. RESULTS: A main effect of laterality was found in radial, axial, and mean diffusivity for the tibial nerve. Axial diffusivity was found to be lateralized in the sciatic nerve. When evaluating mean MTR, a main effect of laterality was found for each nerve division. A main effect of sex was found in the tibial and fibular nerve fiber bundles. CONCLUSION: For the evaluation of nerve measures using DWI and MTI, in either healthy or disease states, consideration of underlying biological metrics of laterality in peripheral nerve fiber characteristics need to considered for data analysis. Integrating knowledge regarding biological laterality of peripheral nerve microstructure may be applied to improve how we diagnosis pain disorders, how we track patients’ recovery and how we forecast pain chronification