290 research outputs found

    Making a case for introspection

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    Defending first-person introspective access to own mental states, we argue against Carruthers' claim of mindreading being prior to meta-cognition and for a fundamental difference between how we understand our own and others' mental states. We conclude that a model based on one mechanism but involving two different kinds of access for self and other is sufficient and more consistent with the evidence

    First principles studies of band offsets at heterojunctions and of surface reconstruction using Gaussian dual-space density functional theory

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    The use of localized Gaussian basis functions for large scale first principles density functional calculations with periodic boundary conditions (PBC) in 2 dimensions and 3 dimensions has been made possible by using a dual space approach. This new method is applied to the study of electronic properties of II–VI (II=Zn, Cd, Hg; VI=S, Se, Te, Po) and III–V (III=Al, Ga; V=As, N) semiconductors. Valence band offsets of heterojunctions are calculated including both bulk contributions and interfacial contributions. The results agree very well with available experimental data. The p(2 × 1) cation terminated surface reconstructions of CdTe and HgTe (100) are calculated using the local density approximation (LDA) with two-dimensional PBC and also using the ab initio Hartree–Fock (HF) method with a finite cluster. The LDA and HF results do not agree very well

    Knowing me, knowing you: Spontaneous use of mentalistic language for self and other in autism

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    Recent studies on mentalizing have shown that autistic individuals who pass explicit mentalizing tasks may still have difficulties with implicit mentalizing tasks. This study explores implicit mentalizing by examining spontaneous speech that is likely to contain mentalistic expressions. The spontaneous production of meta-statements provides a clear measure for implicit mentalizing that is unlikely to be learned through experience. We examined the self- and other-descriptions of highly verbally able autistic and non-autistic adults in terms of their spontaneous use of mentalistic language and meta-representational utterances through quantitative and qualitative analysis. We devised a hierarchical coding system that allowed us to study the types of statements produced in comparable conditions for the self and for a familiar other. The descriptions of autistic participants revealed less mentalistic content relating to psychological traits and meta-statements. References to physical traits were similar between groups. Within each group, participants produced a similar pattern of types of mental utterance across ‘self’ and ‘other’ conditions. This suggests that autistic individuals show a unique pattern of mental-state-representation for both self and other. Meta-statements add a degree of complexity to self- and other-descriptions and to the understanding of mental states; their reduction in autism provides evidence for implicit mentalizing difficulties

    Categorization of compensatory motions in transradial myoelectric prosthesis users

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    Background: Prosthesis users perform various compensatory motions to accommodate for the loss of the hand and wrist as well as the reduced functionality of a prosthetic hand. Objectives: Investigate different compensation strategies that are performed by prosthesis users. Study Design: Comparative analysis Methods: 20 able-bodied subjects and 4 prosthesis users performed a set of bimanual activities. Movements of the trunk and head were recorded using a motion capture system, and a digital video recorder. Clinical motion angles were calculated to assess the compensatory motions made by the prosthesis users. The video recording also assisted in visually identifying the compensations. Results: Compensatory motions by the prosthesis users were evident in the tasks performed (slicing and stirring activities) as compared to the benchmark of able-bodied subjects. Compensations took the form of a measured increase in range of motion, an observed adoption of a new posture during task execution, and pre-positioning of items in the workspace prior to initiating a given task. Conclusion: Compensatory motions were performed by prosthesis users during the selected tasks. These can be categorized into three different types of compensations

    Unveiling spatial variability within the Dotson Melt Channel through high-resolution basal melt rates from the Reference Elevation Model of Antarctica

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    The intrusion of Circumpolar Deep Water in the Amundsen and Bellingshausen Sea embayments of Antarctica causes ice shelves in the region to melt from below, potentially putting their stability at risk. Earlier studies have shown how digital elevation models can be used to obtain ice shelf basal melt rates at a high spatial resolution. However, there has been limited availability of high-resolution elevation data, a gap the Reference Elevation Model of Antarctica (REMA) has filled. In this study we use a novel combination of REMA and CryoSat-2 elevation data to obtain high-resolution basal melt rates of the Dotson Ice Shelf in a Lagrangian framework, at a 50 m spatial posting on a 3-yearly temporal resolution. We present a novel method: Basal melt rates Using REMA and Google Earth Engine (BURGEE). The high resolution of BURGEE is supported through a sensitivity study of the Lagrangian displacement. The high-resolution basal melt rates show a good agreement with an earlier basal melt product based on CryoSat-2. Both products show a wide melt channel extending from the grounding line to the ice front, but our high-resolution product indicates that the pathway and spatial variability of this channel is influenced by a pinning point on the ice shelf. This result emphasizes the importance of high-resolution basal melt rates to expand our understanding of channel formation and melt patterns. BURGEE can be expanded to a pan-Antarctic study of high-resolution basal melt rates. This will provide a better picture of the (in)stability of Antarctic ice shelves.</p

    Mesoporous core-shell silica nanoparticles with anti-fouling properties for ovarian cancer therapy

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    Mesoporous silica nanoparticles (MSNPs) have many potential applications in biomedical fields. However, when MSNPs are exposed to plasma, protein adsorption leads to opsonization and decreases blood circulation time. A new multifunctional nanodevice based on polyethylenimine (PEI) coated core-shell Fe⁠3O⁠4@SiO⁠2 MSNPs with a zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) surface was designed to minimize unspecific protein adhesion. Particle size measurements demonstrated an excellent non-fouling capacity in solutions containing Bovine Serum Albumin (BSA) and Fetal Bovine Serum (FBS) plasma proteins. The system was used in this study to co-deliver two different cargos: siRNA and daunorubicin. Anti-TWIST siRNA plays critical role in modulating knockdown of TWIST and sensitizing cells to chemotherapeutics such as daunorubicin for ovarian cancer therapy. The drug was released in response to externally controlled oscillating magnetic fields (OMF). siRNA (siGFP) silenced expression of green fluorescence protein (GFP) in Ovcar8 cancer cells, demonstrating the incorporation of core shell MSNPs into cells and siGFP delivery. The synergistic effect of the co-release of anti-TWIST-siRNA loaded in the PEI and daunorubicin loaded in NPs’ pores caused increased cytotoxicity in Ovcar8 of up to 50% from both zwitteronic and non-zwitteronic NPs. The system is the first example of silencing by anti-TWITS-siRNA/daunorubicin co-delivered using zwitterionic core-shell nanoparticles with low-fouling adsorption. This engineered multifunctional approach may provide therapeutic potential for the treatment of currently incurable ovarian cáncer

    Investigation of fiber/matrix adhesion: test speed and specimen shape effects in the cylinder test

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    The cylinder test, developed from the microdroplet test, was adapted to assess the interfacial adhesion strength between fiber and matrix. The sensitivity of cylinder test to pull-out speed and specimen geometry was measured. It was established that the effect of test speed can be described as a superposition of two opposite, simultaneous effects which have been modeled mathematically by fitting two parameter Weibull curves on the measured datas. Effects of the cylinder size and its geometrical relation on the measured strength values have been analyzed by finite element method. It was concluded that the geometry has a direct influence on the stress formation. Based on the results achieved, recommendations were given on how to perform the novel single fiber cylinder test

    First principles studies of band offsets at heterojunctions and of surface reconstruction using Gaussian dual-space density functional theory

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    The use of localized Gaussian basis functions for large scale first principles density functional calculations with periodic boundary conditions ͑PBC͒ in 2 dimensions and 3 dimensions has been made possible by using a dual space approach. This new method is applied to the study of electronic properties of II-VI ͑IIϭZn, Cd, Hg; VIϭS, Se, Te, Po͒ and III-V ͑IIIϭAl, Ga; VϭAs, N͒ semiconductors. Valence band offsets of heterojunctions are calculated including both bulk contributions and interfacial contributions. The results agree very well with available experimental data. The p͑2ϫ1͒ cation terminated surface reconstructions of CdTe and HgTe ͑100͒ are calculated using the local density approximation ͑LDA͒ with two-dimensional PBC and also using the ab initio Hartree-Fock ͑HF͒ method with a finite cluster. The LDA and HF results do not agree very well

    Spin relaxation in (110) and (001) InAs/GaSb superlattices

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    We report an enhancement of the electron spin relaxation time (T1) in a (110) InAs/GaSb superlattice by more than an order of magnitude (25 times) relative to the corresponding (001) structure. The spin dynamics were measured using polarization sensitive pump probe techniques and a mid-infrared, subpicosecond PPLN OPO. Longer T1 times in (110) superlattices are attributed to the suppression of the native interface asymmetry and bulk inversion asymmetry contributions to the precessional D'yakonov Perel spin relaxation process. Calculations using a nonperturbative 14-band nanostructure model give good agreement with experiment and indicate that possible structural inversion asymmetry contributions to T1 associated with compositional mixing at the superlattice interfaces may limit the observed spin lifetime in (110) superlattices. Our findings have implications for potential spintronics applications using InAs/GaSb heterostructures.Comment: 4 pages, 2 figure
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