Electron-Deficient N-Alkyloyl Derivatives of Thienopyrrole-4,6-dione Yield Efficient Polymer Solar Cells with Open-Circuit Voltages > 1 V

Poly(benzo[1,2-b:4,5-b′]dithiophene–thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymer donors yield some of the highest open-circuit voltages (VOC, ca. 0.9 V) and fill factors (FF, ca. 70%) in conventional bulk-heterojunction (BHJ) solar cells with PCBM acceptors. Recent work has shown that the incorporation of ring substituents into the side chains of the BDT motifs in PBDTTPD can induce subtle variations in material properties, resulting in an increase of the BHJ device VOC to ∼1 V. In this contribution, we report on the synthesis of N-alkyloyl-substituted TPD motifs (TPD(CO)) and show that the electron-deficient motifs can further lower both the polymer LUMO and HOMO levels, yielding device VOC > 1 V (up to ca. 1.1 V) in BHJ solar cells with PCBM. Despite the high VOC achieved (i.e., low polymer HOMO), BHJ devices cast from TPD(CO)-based polymer donors can reach power conversion efficiencies (PCEs) of up to 6.7%, making these promising systems for use in the high-band-gap cell of tandem solar cells

The effect of acute exercise on encoding and consolidation of long-term memory

Evidence supports that acute exercise benefits long-term memory. However, it is unclear whether these effects are due to benefits to encoding or consolidation. The purpose of this study was to more effectively isolate encoding and consolidation to advance our understanding of the specific nature of the effects of exercise on long-term memory. Using a within-subject design, participants completed a control session (no exercise), an encoding and consolidation condition (exercise prior to exposure to the memory task, E + C), and a consolidation condition (exercise following exposure). The exercise was 30min of moderate-intensity cycling. Memory was assessed using the Rey Auditory Verbal Learning Test with recall assessed at 60 min and recall and recognition assessed at 24 hr. Results showed that the E + C condition had significantly better recall at 60 min and 24 hr than the no-exercise condition. This provides additional evidence that acute exercise benefits encoding more than consolidation

Effects of an acute bout of exercise on memory in 6th grade children

Research supports the positive effects of exercise on cognitive performance by children. However, a limited number of studies have explored the effects specifically on memory. The purpose of this study was to compare the effects of an acute bout of exercise on learning, short-term memory, and long-term memory in a sample of children. Children were randomly assigned to an exercise condition or to a no-treatment control condition and then performed repeated trials on an auditory verbal learning task. In the exercise condition, participants performed the PACER task, an aerobic fitness assessment, in their physical education class before performing the memory task. In the control condition, participants performed the memory task at the beginning of their physical education class. Results showed that participants in the exercise condition demonstrated significantly better learning of the word lists and significantly better recall of the words after a brief delay. There were not significant differences in recognition of the words after an approximately 24-hr delay. These results provide evidence in a school setting that an acute bout of exercise provides benefits for verbal learning and long-term memory. Future research should be designed to identify the extent to which these findings translate to academic measures

Effects of acute exercise on long-term memory

In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of three groups: exercise prior to exposure, exercise after exposure, or no-exercise. Exercise consisted of 30 min on a cycle ergometer, including 20 min at moderate intensity. Only the exercise-prior group recalled significantly more than the control group (p < .05). Differences among the exercise groups failed to reach significance (p = .09). Results indicated that acute exercise positively influenced recall and that exercise timing relative to memory task may have an impact on this effect

The effects of physical activity on attention deficit hyperactivity disorder symptoms: The evidence

Evidence supports the beneficial effects of physical activity (PA) on cognitive performance and suggests that effects might be particularly large for children. However, limited research has explored PA as a means of managing behavioral symptoms and improving cognitive performance of children with attention deficit hyperactivity disorder (ADHD). The etiology of ADHD and the putative mechanisms for the effects of PA on cognitive performance suggest that PA might be especially important for this population.ObjectiveThe purpose of this paper is to review the literature regarding the potential of PA for ADHD symptom management, particularly in regard to behavioral and cognitive symptoms.MethodsLiterature was reviewed for published and unpublished research specifically examining the effects of PA on cognitive and/or behavioral symptoms of ADHD. Additionally, potential mechanisms were addressed.ResultsAlbeit limited, current research generally supports the potential for acute and chronic PA to mitigate ADHD symptoms.ConclusionGiven the generally supportive extant literature and the challenges that face children with ADHD, future research exploring the potential of PA with this population is advocated

The effects of acute exercise on memory and brain-derived neurotrophic factor (BDNF)

Acute exercise benefits cognition, and some evidence suggests that brain-derived neurotrophic factor (BDNF) plays a role in this effect. The purpose of this study was to explore the dose–response relationship between exercise intensity, memory, and BDNF. Young adults completed 3 exercise sessions at different intensities relative to ventilator threshold (Vt) (VO2max, Vt – 20%, Vt + 20%). For each session, participants exercised for approximately 30 min. Following exercise, they performed the Rey Auditory Verbal Learning Test (RAVLT) to assess short-term memory, learning, and long-term memory recall. Twenty-four hours later, they completed the RAVLT recognition trial, which provided another measure of long-term memory. Blood was drawn before exercise, immediately postexercise, and after the 30-min recall test. Results indicated that long-term memory as assessed after the 24-hr delay differed as a function of exercise intensity with the largest benefits observed following maximal intensity exercise. BDNF data showed a significant increase in response to exercise; however, there were no differences relative to exercise intensity and there were no significant associations between BDNF and memory. Future research is warranted so that we can better understand how to use exercise to benefit cognitive performance

The effects of acute exercise on cognitive performance: A meta-analysis

There is a substantial body of literature related to the effects of a single session of exercise on cognitive performance. The premise underlying this research is that physiological changes in response to exercise have implications for cognitive function. This literature has been reviewed both narratively and meta-analytically and, although the research findings are mixed, researchers have generally concluded that there is a small positive effect. The purpose of this meta-analysis was to provide an updated comprehensive analysis of the extant literature on acute exercise and cognitive performance and to explore the effects of moderators that have implications for mechanisms of the effects. Searches of electronic databases and examinations of reference lists from relevant studies resulted in 79 studies meeting inclusion criteria. Consistent with past findings, analyses indicated that the overall effect was positive and small (g = 0.097 n = 1034). Positive and small effects were also found in all three acute exercise paradigms: during exercise (g = 0.101; 95% confidence interval [CI]; 0.041–0.160), immediately following exercise (g = 0.108; 95% CI; 0.069–0.147), and after a delay (g = 0.103; 95% CI; 0.035–0.170). Examination of potential moderators indicated that exercise duration, exercise intensity, type of cognitive performance assessed, and participant fitness were significant moderators. In conclusion, the effects of acute exercise on cognitive performance are generally small; however, larger effects are possible for particular cognitive outcomes and when specific exercise parameters are used

Brothers leading healthy lives: outcomes from the pilot testing of a culturally and contextually congruent HIV prevention intervention for black male college students

We used a treatment group-only design to pilot test a newly developed intervention to increase condom use among higher risk heterosexually active African American/black male college students. A community-based participatory research partnership developed the intervention called Brothers Leading Healthy Lives. Following an initial screening of 245 men, 81 eligible men were contacted for participation. Of the 64 men who agreed to participate, 57 completed the intervention and 54 of those completed the 3-monthfollow-up assessment, for a 93% completion rate. Results show significant changes between the baseline and 3-month follow-up assessments in behavioral outcomes, including reductions in unprotected sex, increase in protection during last intercourse, and fewer condom use errors. Most potential mediators (knowledge, attitudes, intentions, and condom use self-efficacy) also changed significantly in the expected direction. These demonstrated changes provide good evidence that men exposed to this intervention will see changes that reduce their risk for HIV