Photoshop with friends: A synchronous learning community for graphic design

Photoshop with Friends is an online community of learners exchanging just-in-time help on graphic design tasks. The system attempts to provide an interactive, visual, context-aware, and personalized mode of learning. Developed as a Facebook application, Photoshop with Friends allows users to help each other in live sessions, with built-in screen sharing, recording, and voice chat support. Major design decisions are guided by two laboratory studies that identified challenges in learning graphic design skills on the web

RiceWrist Robotic Device for Upper Limb Training: Feasibility Study and Case Report of Two Tetraplegic Persons with Spinal Cord Injury

Regaining upper extremity function is the primary concern of persons with tetraplegia caused by spinal cord injury (SCI). Robotic rehabilitation has been inadequately tested and underutilized in rehabilitation of the upper extremity in the SCI population. Given the acceptance of robotic training in stroke rehabilitation and SCI gait training, coupled with recent evidence that the spinal cord, like the brain, demonstrates plasticity that can be enhanced by repetitive movement training such as that available with robotic devices, it is probable that robotic upper extremity training of persons with SCI could be clinically beneficial. The primary goal of this pilot study was to test the feasibility of using a novel robotic device –the RiceWrist Exoskeleton- for rehabilitation of the upper limbs (UL) of two tetraplegic persons with incomplete SCI. Two pilot experiments were conducted. Experiment 1was the first novel attempt to administer treatment with the RiceWrist. The left UL of a tetraplegic subject was treated during seven therapy sessions. The subject’s feedback and the investigator’s obser-vations were used to enhance the robotic device and the corresponding graphical-interface. In Experiment 2, a second tetra-plegic subject underwent 10 three-hour training sessions administered by a physical therapist. Smoothness factor (FS) –a new measure developed in Experiment 1- was used as the primary outcome to test the subject’s performance before and after the training. The RiceWrist was modified according to the feedback obtained in Experiment 1. Thereafter, the device was suc-cessfully administered for upper limb training of the tetraplegic individual. Noticeable improvements in FS were observed for the stronger arm of the subject who completed 10 sessions of training. Improvements were also observed in the subject’s hand according to the Jebsen-Taylor Hand Function Test. Results from this study suggest a potential application of the RiceWrist for rehabilitation of SCI individuals and offer valuable information regarding development of UL robotic devices for this population

Logic gates at the surface code threshold: Superconducting qubits poised for fault-tolerant quantum computing

A quantum computer can solve hard problems - such as prime factoring, database searching, and quantum simulation - at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection, by distributing a logical state among many physical qubits via quantum entanglement. Superconductivity is an appealing platform, as it allows for constructing large quantum circuits, and is compatible with microfabrication. For superconducting qubits the surface code is a natural choice for error correction, as it uses only nearest-neighbour coupling and rapidly-cycled entangling gates. The gate fidelity requirements are modest: The per-step fidelity threshold is only about 99%. Here, we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92% and a two-qubit gate fidelity up to 99.4%. This places Josephson quantum computing at the fault-tolerant threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger (GHZ) state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.Comment: 15 pages, 13 figures, including supplementary materia

Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue

The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines

Monocytes regulate the mechanism of T-cell death by inducing Fas-mediated apoptosis during bacterial infection.

Monocytes and T-cells are critical to the host response to acute bacterial infection but monocytes are primarily viewed as amplifying the inflammatory signal. The mechanisms of cell death regulating T-cell numbers at sites of infection are incompletely characterized. T-cell death in cultures of peripheral blood mononuclear cells (PBMC) showed 'classic' features of apoptosis following exposure to pneumococci. Conversely, purified CD3(+) T-cells cultured with pneumococci demonstrated necrosis with membrane permeabilization. The death of purified CD3(+) T-cells was not inhibited by necrostatin, but required the bacterial toxin pneumolysin. Apoptosis of CD3(+) T-cells in PBMC cultures required 'classical' CD14(+) monocytes, which enhanced T-cell activation. CD3(+) T-cell death was enhanced in HIV-seropositive individuals. Monocyte-mediated CD3(+) T-cell apoptotic death was Fas-dependent both in vitro and in vivo. In the early stages of the T-cell dependent host response to pneumococci reduced Fas ligand mediated T-cell apoptosis was associated with decreased bacterial clearance in the lung and increased bacteremia. In summary monocytes converted pathogen-associated necrosis into Fas-dependent apoptosis and regulated levels of activated T-cells at sites of acute bacterial infection. These changes were associated with enhanced bacterial clearance in the lung and reduced levels of invasive pneumococcal disease

Protective Contributions against Invasive Streptococcus pneumoniae Pneumonia of Antibody and Th17-Cell Responses to Nasopharyngeal Colonisation

The nasopharyngeal commensal bacteria Streptococcus pneumoniae is also a frequent cause of serious infections. Nasopharyngeal colonisation with S. pneumoniae inhibits subsequent re-colonisation by inducing Th17-cell adaptive responses, whereas vaccination prevents invasive infections by inducing antibodies to S. pneumoniae capsular polysaccharides. In contrast, protection against invasive infection after nasopharyngeal colonisation with mutant S. pneumoniae strains was associated with antibody responses to protein antigens. The role of colonisation-induced Th17-cell responses during subsequent invasive infections is unknown. Using mouse models, we show that previous colonisation with S. pneumoniae protects against subsequent lethal pneumonia mainly by preventing bacteraemia with a more modest effect on local control of infection within the lung. Previous colonisation resulted in CD4-dependent increased levels of Th17-cell cytokines during subsequent infectious challenge. However, mice depleted of CD4 cells prior to challenge remained protected against bacteraemia, whereas no protection was seen in antibody deficient mice and similar protection could be achieved through passive transfer of serum. Serum from colonised mice but not antibody deficient mice promoted phagocytosis of S. pneumoniae, and previously colonised mice were able to rapidly clear S. pneumoniae from the blood after intravenous inoculation. Thus, despite priming for a Th17-cell response during subsequent infection, the protective effects of prior colonisation in this model was not dependent on CD4 cells but on rapid clearance of bacteria from the blood by antibody-mediated phagocytosis. These data suggest that whilst nasopharyngeal colonisation induces a range of immune responses, the effective protective responses depend upon the site of subsequent infectio

First direct measurement of 22^{22}Mg(α\alpha,p)25^{25}Al and implications for X-ray burst model-observation comparisons

Type-I X-ray burst (XRB) light curves are sensitive to the model's nuclear input and consequently affects the model-observation comparisons. $^{22}$Mg($\alpha$,p)$^{25}$Al is among the most important reactions which directly impact the XRB light curve. We report the first direct measurement of $^{22}$Mg($\alpha$,p)$^{25}$Al using the Active Target Time Projection Chamber. XRB light curve model-observation comparison for the source $\tt{GS 1826-24}$ using new reaction rate implies a less-compact neutron star than previously inferred. Additionally, our result removes an important uncertainty in XRB model calculations that previously hindered extraction of the neutron star compactness

The truth about co-benefits: a multidimensional feasibility assessment for thailand and beyond

Research has yielded increasingly robust estimates of the co-benefits from mitigating climate change while reducing air pollution, improving health, and meeting other development needs. Though quantifying these often hidden benefits could ease cost concerns and lower technological constraints for development-friendly climate solutions, achieving co-benefits frequently requires overcoming difficult-to-measure social and institutional barriers. This study extends insights from research focusing on quantitatively assessing the feasibility of a 1.5 °C future to build a multidimensional framework for measuring different barriers to achieving co-benefits. The framework offers a novel yet generalizable approach for bringing context-appropriate assessments of different dimensions of feasibility into the integrated assessment modelling that underpins work on co-benefits. It then outlines five steps for applying that framework to evaluate the size of different barriers for transport, agricultural and residential energy co-benefit solutions in Thailand. The results demonstrate that the sum of the delays from social/institutional barriers exceed economic/technological barriers for four out of six studied solutions. These delays also lead to increases of 24% to 31% in PM2.5 emissions relative to a no-barriers effective implementation scenario between 2015 and 2030 and 2040. The feasibility framework can be integrated into not only national policy scenarios but also project assessments, following trends in carbon finance. An international barriers database as well as strengthening links to work on barriers and technological diffusion, transaction costs, and multi-level transitions can also help spread multi-dimensional feasibility assessments across countries and scales