Switching attention deficits in post-stroke individuals with different aphasia types.

BACKGROUND: Previous studies have shown that individuals with aphasia have impairments in switching attention compared to healthy controls. However, there is insufficient information about the characteristics of switching attention within one task and whether attention deficits vary depending on aphasia type and lesion location. We aimed to address these knowledge gaps by investigating characteristics of switching attention within one type of task in participants with different types of aphasia and distinct lesion sites. METHOD: Forty individuals with post-stroke aphasia (20 with non-fluent aphasia and frontal lobe damage, and 20 with fluent aphasia and temporal lobe damage) and 20 neurologically healthy age-matched individuals performed an attention switching task. They listened to sequences of high-pitched and low-pitched tones that were presented to them one by one, tallied them separately, and, at the end of each sequence, had to say how many high- and low-pitched tones they had heard. RESULTS: Participants with aphasia performed significantly worse on the task compared to healthy controls, and the performance of two aphasia groups also differed. Specifically, individuals with both aphasia types made more errors than healthy individuals, and the participants with non-fluent aphasia responded more slowly than controls, while reaction times of the participants with fluent aphasia did not differ significantly from those of controls. Also, the two groups of participants with aphasia differed significantly in accuracy, with individuals in the non-fluent group making more errors. CONCLUSIONS: The data demonstrated that people with different types of aphasia have distinct impairments in switching attention. Since cognitive deficits impact language performance, this information is important for differentially addressing their language problems and selecting more specific and optimal rehabilitation programs that target different underlying mechanisms

Electrochemical Characterisation of Bio-Bottle-Voltaic (BBV) Systems Operated with Algae and Built with Recycled Materials.

Photobioelectrochemical systems are an emerging possibility for renewable energy. By exploiting photosynthesis, they transform the energy of light into electricity. This study evaluates a simple, scalable bioelectrochemical system built from recycled plastic bottles, equipped with an anode made from recycled aluminum, and operated with the green alga Chlorella sorokiniana. We tested whether such a system, referred to as a bio-bottle-voltaic (BBV) device, could operate outdoors for a prolonged time period of 35 days. Electrochemical characterisation was conducted by measuring the drop in potential between the anode and the cathode, and this value was used to calculate the rate of charge accumulation. The BBV systems were initially able to deliver ~500 mC·bottle−1·day−1, which increased throughout the experimental run to a maximum of ~2000 mC·bottle−1·day−1. The electrical output was consistently and significantly higher than that of the abiotic BBV system operated without algal cells (~100 mC·bottle−1·day−1). The analysis of the rate of algal biomass accumulation supported the hypothesis that harvesting a proportion of electrons from the algal cells does not significantly perturb the rate of algal growth. Our finding demonstrates that bioelectrochemical systems can be built using recycled components. Prototypes of these systems have been displayed in public events; they could serve as educational toolkits in schools and could also offer a solution for powering low-energy devices off-grid

Acute myeloid leukemia of donor origin after allogeneic stem cell transplantation from a sibling who harbors germline XPD and XRCC3 homozygous polymorphisms

A 54-year-old woman was diagnosed with infiltrative ductal breast carcinoma. Two years after treatment, the patient developed an acute myeloid leukemia (AML) which harbored del(11q23) in 8% of the blast cells. The patient was submitted for allogeneic stem cell transplantation (aSCT) from her HLA-compatible sister. Ten months after transplantation, she relapsed with an AML with basophilic maturation characterized by CD45low CD33high, CD117+, CD13-/+, HLA Drhigh, CD123high, and CD203c+ blast cells lacking expression of CD7, CD10, CD34, CD15, CD14, CD56, CD36, CD64, and cytoplasmic tryptase. Karyotype analysis showed the emergence of a new clone with t(2;14) and FISH analysis indicated the presence of MLL gene rearrangement consistent with del(11q23). Interestingly, AML blast cell DNA tested with microsatellite markers showed the same pattern as the donor's, suggesting that this AML emerged from donor cells. Additionally, polymorphisms of the XPA, XPD, XRCC1, XRCC3 and RAD51 DNA repair genes revealed three unfavorable alleles with low DNA repair capacity

Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

Introduction Deficits in working memory (WM) are amongst the most widely acknowledged cognitive impairments in aphasia.However, there is still on-going debate what tasks should be used to assess WM in aphasia (Wright & Fergadiotos, 2012). The two main alternatives for this purpose are simplified complex span tasks and N-back tasks. In a typical complex span task, a processing task (e.g., sentence reading), is given along with a set of stimuli (e.g., words) to be remembered for later recall. In N-back tasks, participants are instructed to judge whether an item matches a previous one presented n items before. Proponents of complex span tasks state that these tasks are the gold standard for assessing WM capacity in cognitive psychology and that variations of these tasksare endorsed as valid means of indexing WM capacity within different theoretical frameworks. On the other hand, researchers using N-back tasks state that since these tasks are more language-free in nature, they are more appropriate for indexing cognitive non-linguistic abilities with language-impaired populations. Several investigations comparing the two tasks in healthy controls have demonstrated no relationship between the two tasks (Jaeggi et al., 2010; Kane et al., 2007). Although, limited conflicting findings indicating a significant relationship between the two tasks have also been reported (Schmiedek et al., 2009). Additionally, performance on complex span task in aphasia studies have repeatedly been related to performance on standardized language tests (Sung et al. 2009; Wright & Fergadiotos, 2012), while similar correlations have never found for N-back tasks (Christensen, & Wright, 2010; Mayer & Murray, 2012). The aim of the present study was to directly investigate the relationship between performance on complex span tasks and N-back tasks in aphasia. Methods 32native speakers of Russian with aphasia following left hemisphere stroke participated. Complex span task (modified listening span task, Ivanova & Hallowell, 2014), 2-back and 0-back tasks with words, a test of auditory language comprehension– Quantitative Assessment of Speech in Aphasia (QASA; Tsvetkova et al., 1981) – were administered. Results and discussion No significant correlations were observed between performance on complex span task and N-back tasks.Furthermore, performance on the modified listening span was related to performance on the comprehension subtest of the QASA, while no relationship was found for 2-back and 0-back tasks.Our results mirror studies in healthy controls that demonstrated no relationship between performance on the two tasks(Jaeggi et al., 2010; Kane et al., 2007). Thus although N-back tasks seem similar to traditional complex span measures and may also index abilities related to cognitive processing, the evidence to date does not warrant their direct association with the construct of WM. Implications for future investigation of cognitive deficits in aphasia will be discussed

Digital Urban Orchard: Robotic Manufacturing of Complex Shape

The Digital Urban Orchard, developed during the Applied Research program Open Thesis Fabrication 2015 at IaaC, is a digitally fabricated pavilion located in Barcelona. The 1:1 prototype was realized using 1,681 Redwood sticks of Flanders, maximizing time and cost efficiency thanks to the application of the mass production paradigm. Structural, material and environmental performance have been directly embedded within the computational design process and expressed through the robotic fabrication. The first phase of the project, the wooden structure, combines this process together with the in-situ manual assembly. Within the final cocoon-shape each stick performs a function between main truss, structural stiffener, aquaponics system support, skin support, furniture and platform beam. In the light of the working prototype, Fusta Rob\uf2tica Pavilion 2015, the robotic manufacturing loop process (picking, cutting and placing) also reduced the scrap length and waste production. According to the final position of each stick, these are selected from one of the three starting stick lengths, provided through a custom made feeder. The end edges are shaped according to diverse 3-dimensional angled cuts, thus each stick, varying each time the fabrication loop, informs the robotic fabrication code. The pavilion embodies a habitable and productive urban rooftop, combining soilless aquaponics, parametric design and robotic fabrication processes