47 research outputs found

    Edge effect removal in Fourier ptychographic microscopy via perfect Fourier transformation (PFT)

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    Edge effect may degrade the imaging precision and is caused by the aperiodic image extension of fast Fourier transform (FFT). In this letter, a perfect Fourier transform algorithm termed PFT was reported to remove the artifacts with comparable efficiency to FFT. Although we demonstrated the performance of PFT in Fourier ptychographic microscopy (FPM) only, it can be expanded in any occasion where the conventional FFT is used.Comment: 4 pages, 6 figure

    The Role of Important Non-Parental Adults (VIPs) in the Lives of Older Adolescents: A Comparison of Three Ethnic Groups

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    Previous research has consistently documented the importance of VIPs (mentors or important non-parental adults) in the lives of adolescents. Little is known, however, about whether VIPs play the same important roles across ethnic groups and whether VIPs remain influential when adolescents are older and involved in romantic relationships. The present study compared VIPs of 355 Hispanic, Asian, and European American older adolescents (age range = 17–19 years; M = 18.7 years; 62% female). Results indicated that, despite ethnic differences in their social capital, VIPs’ psychological characteristics (e.g., warmth and acceptance, depressive symptoms, and problem behavior) were similar. VIPs were perceived to have more positive psychological profiles than parents and peers, and in some cases, romantic partners. Moreover, with a few exceptions, the associations between VIP characteristics and adolescent adjustment (e.g., self-esteem, depressive symptoms, and problem behavior) were largely similar across ethnic groups. Finally, VIPs made unique contributions to adolescents’ self-esteem and problem behaviors even after the effects of romantic partners were considered. Implications of the findings are discussed

    Dysfunction in the βII Spectrin-Dependent Cytoskeleton Underlies Human Arrhythmia.

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    Background: The cardiac cytoskeleton plays key roles in maintaining myocyte structural integrity in health and disease. In fact, human mutations in cardiac cytoskeletal elements are tightly linked with cardiac pathologies including myopathies, aortopathies, and dystrophies. Conversely, the link between cytoskeletal protein dysfunction in cardiac electrical activity is not well understood, and often overlooked in the cardiac arrhythmia field. Methods and Results: Here, we uncover a new mechanism for the regulation of cardiac membrane excitability. We report that βII spectrin, an actin-associated molecule, is essential for the post-translational targeting and localization of critical membrane proteins in heart. βII spectrin recruits ankyrin-B to the cardiac dyad, and a novel human mutation in the ankyrin-B gene disrupts the ankyrin-B/βII spectrin interaction leading to severe human arrhythmia phenotypes. Mice lacking cardiac βII spectrin display lethal arrhythmias, aberrant electrical and calcium handling phenotypes, and abnormal expression/localization of cardiac membrane proteins. Mechanistically, βII spectrin regulates the localization of cytoskeletal and plasma membrane/sarcoplasmic reticulum protein complexes that include the Na/Ca exchanger, RyR2, ankyrin-B, actin, and αII spectrin. Finally, we observe accelerated heart failure phenotypes in βII spectrin-deficient mice. Conclusions: Our findings identify βII spectrin as critical for normal myocyte electrical activity, link this molecule to human disease, and provide new insight into the mechanisms underlying cardiac myocyte biology

    Contributions of Dopamine-Related Genes and Environmental Factors to Highly Sensitive Personality: A Multi-Step Neuronal System-Level Approach

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    Traditional behavioral genetic studies (e.g., twin, adoption studies) have shown that human personality has moderate to high heritability, but recent molecular behavioral genetic studies have failed to identify quantitative trait loci (QTL) with consistent effects. The current study adopted a multi-step approach (ANOVA followed by multiple regression and permutation) to assess the cumulative effects of multiple QTLs. Using a system-level (dopamine system) genetic approach, we investigated a personality trait deeply rooted in the nervous system (the Highly Sensitive Personality, HSP). 480 healthy Chinese college students were given the HSP scale and genotyped for 98 representative polymorphisms in all major dopamine neurotransmitter genes. In addition, two environment factors (stressful life events and parental warmth) that have been implicated for their contributions to personality development were included to investigate their relative contributions as compared to genetic factors. In Step 1, using ANOVA, we identified 10 polymorphisms that made statistically significant contributions to HSP. In Step 2, these polymorphism's main effects and interactions were assessed using multiple regression. This model accounted for 15% of the variance of HSP (p<0.001). Recent stressful life events accounted for an additional 2% of the variance. Finally, permutation analyses ascertained the probability of obtaining these findings by chance to be very low, p ranging from 0.001 to 0.006. Dividing these loci by the subsystems of dopamine synthesis, degradation/transport, receptor and modulation, we found that the modulation and receptor subsystems made the most significant contribution to HSP. The results of this study demonstrate the utility of a multi-step neuronal system-level approach in assessing genetic contributions to individual differences in human behavior. It can potentially bridge the gap between the high heritability estimates based on traditional behavioral genetics and the lack of reproducible genetic effects observed currently from molecular genetic studies

    Achieving mainstream nitrogen removal through coupling anammox with denitratation

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    Achieving maintream anammox is critical for energy-neutral sewage treatment. This study presents a new way to achieve mainstream anammox, which couples anammox with denitratation (nitrate reduction to nitrite) instead of nitritation (ammonium oxidation to nitrite). An anoxic/oxic (A/O) biofilm system treating systhetic domestic wastewater was used to demonstrate this concept for over 400 days. This A/O biofilm system achieved a total nitrogen (TN) removal efficiency of 80 ± 4% from the influent with a low C/N ratio of 2.6 and a TN concentration of 60.5 mg/L. Nitrogen removal via anammox was found to account for 70% of dinitrogen production in the anoxic reactor. Batch tests confirmed that the anoxic biofilm could oxidize ammonium using nitrite as electron acceptor, and that it had a higher nitrate reduction rate than the nitrite reduction rate, thus producing nitrite for the anammox reaction. Metagenomic analysis showed that Candidatus Jettenia caeni and Candidatus Kuenenia stuttgartiensis were the top two dominant species in anoxic biofilm. Genes involved in the metabolism of the anammox process were detected in anoxic biofilm. The abundance of nitrate reductase (73360 hits) was much higher than nitrite reductase (13114 hits) in anoxic biofilm. This system can be easily integrated with the high-rate activated sludge technology, which produces an effluent with a low C/N ratio. While this new design consumes 21% more oxygen in comparison to the currently studied nitritation/anammox process, the nitrite-producing process appears to be more stable

    Effect of the Addition of Different Amounts of Aramid Fibers on Metal Friction and Wear during Mixing

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    Studies show that the long-term operation of a rubber mixer results in wear at the end face of the mixer. End face wear increases the gap between the mixing chamber and the end face, resulting in leakage and a reduction in the mixing performance, affecting the final product’s quality. Therefore, it is essential to investigate the wear of the metal face during the mixing process. The present study added aramid fibers to a rubber compound using a mechanical blender to obtain a composite material. Then, the influence of the aramid fibers on the metal friction and wear of the end face of the mixer was analyzed. This article introduces the concept of the wear ratio and explores the friction and wear of metals from the perspective of formulation technology for the first time. With the addition of aramid fibers, the proportion of abrasive wear of rubber on metal decreased, and the proportion of corrosive wear increased during the mixing process; however, when the addition of aramid fibers exceeded 3 phr, the balance of abrasive wear of rubber on metal increased and the proportion of corrosive wear decreased. It was found that aramid fibers have the property of friction reduction, which reduces the wear of the rubber blend on the metal. When the amount of aramid fibers added was 3 phr, the amount of abrasion of the rubber compound on the metal was the lowest
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