A plug-and-play ripple mitigation approach for DC-links in hybrid systems

© 2016 IEEE.In this paper, a plug-and-play ripple mitigation technique is proposed. It requires only the sensing of the DC-link voltage and can operate fully independently to remove the low-frequency voltage ripple. The proposed technique is nonintrusive to the existing hardware and enables hot-swap operation without disrupting the normal functionality of the existing power system. It is user-friendly, modular and suitable for plug-and-play operation. The experimental results demonstrate the effectiveness of the ripple-mitigation capability of the proposed device. The DC-link voltage ripple in a 110 W miniature hybrid system comprising an AC/DC converter and two resistive loads is shown to be significantly reduced from 61 V to only 3.3 V. Moreover, it is shown that with the proposed device, the system reliability has been improved by alleviating the components' thermal stresses

A design methodology for smart LED lighting systems powered by weakly regulated renewable power grids

The increasing use of intermittent renewable energy sources to decarbonize electric power generation is expected to introduce dynamic instability to the mains. This situation is of particular concern for mini-grids or isolated grids in which wind and/or solar power sources are the dominant or the sole power sources. In this paper, we utilize the photo-electro-thermal theory to develop a design methodology for LED lighting systems for weakly regulated voltage sources, with the objectives of minimizing the fluctuation of the human luminous perception and adopting reliable LED driver with long lifetime and robustness against extreme weather conditions. The proposed LED system, practically verified in a 10 kVA small power grid driven by an ac voltage source and a wind energy simulator, can be considered as a smart load with its load demand following the power generation. A typical swing of 40 V in the mains will cause only 15% actual light variation in a 132 W LED system when compared with 40% change in 150 W high-pressure-sodium lamp system. The design methodology enables future large-scale LED systems to be designed as a new generation of smart loads that can adapt to the voltage and power fluctuations arising from the intermittent nature of renewable energy sources. © 2011 IEEE.published_or_final_versio

Toward integration of reading and service learning through an interdisciplinary program

This study examined the effect of an interdisciplinary program of reading and service learning on the cognitive and affective development of university students in Hong Kong. As Nussbaum (1997) stated, literature plays a vital role in educating citizens of the world through its narrative imagination and its power of promoting understanding and empathy toward the life of others. Halstead and Pike (2006) also emphasized that art can foster reflection upon action and bring about change in behavior as a result of perspective change. In this study, 24 freshmen read literary works under the theme of children's welfare and explored issues related to the welfare of children worldwide. Their reflections on these materials were expressed in writing and in a presentation. In the following semester, the students participated in voluntary services within and outside Hong Kong. All students completed a questionnaire on their humanistic concerns and sense of global citizenship at the beginning and the end of the project. Results showed that students were conscious of their changes after joining the program and stated their growth in values and knowledge. The pre-post-t-test analysis suggested that students had made significant improvement in the following areas: (1) their attitude toward serving others, especially in their personal and social values; (2) their engagement in reading literary and nonfiction works which reflect social and moral issues of the world; (3) their attention to world affairs; (4) their concern for the underprivileged; and (5) awareness of their potential in helping the poor. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Variation of structural, electrical, and optical properties of Zn <inf>1-x</inf>Mg <inf>x</inf>O thin films

Zn 1-xMg xO thin films on (001) sapphire substrates were deposited using pulsed laser deposition. As the substrate temperature increased, the Mg content in the Zn 1-xMg xO thin films increased and the photoluminescence (PL) peak position of the Zn 1-xMg xO thin films shifted from 370 to 356 nm, indicating a band gap expansion. Variations of the structural, electrical, and optical properties of Zn 1-xMgO thin films have been observed and analyzed by x-ray diffraction, Hall measurements, and PL measurements. © 2006 American Institute of Physics

Voluntary wheel running reverses the decrease in subventricular zone neurogenesis caused by corticosterone

Adult neurogenesis within the dentate gyrus of the hippocampus can be increased by voluntary exercise but is suppressed under stress, such as with corticosterone (CORT). However, the effects of exercise and corticosterone on the cell proliferation of the other traditional neurogenic site, the subventricular zone (SVZ) have been reported with controversial results. In addition, the co-treatment effects of voluntary exercise and corticosterone have not been investigated. This study aims to determine whether corticosterone can suppress cell proliferation in the SVZ, and whether this can be reversed by voluntary exercise. In the present study, the effect of chronic (4 weeks) corticosterone treatment and wheel running simultaneously on the SVZ cell proliferation of adult Sprague-Dawley rats was examined. The results showed that cell proliferation indicated by bromodeoxyuridine (BrdU) was increased by voluntary wheel running whereas it was decreased by corticosterone treatment within the SVZ of the rats without running. For the rats with both corticosterone treatment and wheel running, it was found that the number of BrdU-labeled cells was approximately at the same level as the vehicle control group. Furthermore, these proliferating cells expressed doublecortin (DCX), a migrating neuroblast marker. Wheel running increased the percentage of BrdU-labeled cells expressing DCX in the SVZ whereas corticosterone treatment decreased this percentage. Thus, chronic injection of corticosterone can decrease the number of proliferating cells while wheel running can reverse the decrease in cell proliferation within the SVZ to normal levels. In addition, corticosterone can suppress the cell differentiation within the SVZ and this was alleviated by wheel running as indicated by the double-labeling of BrdU and DCX.published_or_final_versio

Developing Children's Oral Health Assessment Toolkits Using Machine Learning Algorithm.

ObjectivesEvaluating children's oral health status and treatment needs is challenging. We aim to build oral health assessment toolkits to predict Children's Oral Health Status Index (COHSI) score and referral for treatment needs (RFTN) of oral health. Parent and Child toolkits consist of short-form survey items (12 for children and 8 for parents) with and without children's demographic information (7 questions) to predict the child's oral health status and need for treatment.MethodsData were collected from 12 dental practices in Los Angeles County from 2015 to 2016. We predicted COHSI score and RFTN using random Bootstrap samples with manually introduced Gaussian noise together with machine learning algorithms, such as Extreme Gradient Boosting and Naive Bayesian algorithms (using R). The toolkits predicted the probability of treatment needs and the COHSI score with percentile (ranking). The performance of the toolkits was evaluated internally and externally by residual mean square error (RMSE), correlation, sensitivity and specificity.ResultsThe toolkits were developed based on survey responses from 545 families with children aged 2 to 17 y. The sensitivity and specificity for predicting RFTN were 93% and 49% respectively with the external data. The correlation(s) between predicted and clinically determined COHSI was 0.88 (and 0.91 for its percentile). The RMSEs of the COHSI toolkit were 4.2 for COHSI (and 1.3 for its percentile).ConclusionsSurvey responses from children and their parents/guardians are predictive for clinical outcomes. The toolkits can be used by oral health programs at baseline among school populations. The toolkits can also be used to quantify differences between pre- and post-dental care program implementation. The toolkits' predicted oral health scores can be used to stratify samples in oral health research.Knowledge transfer statementThis study creates the oral health toolkits that combine self- and proxy- reported short forms with children's demographic characteristics to predict children's oral health and treatment needs using Machine Learning algorithms. The toolkits can be used by oral health programs at baseline among school populations to quantify differences between pre and post dental care program implementation. The toolkits can also be used to stratify samples according to the treatment needs and oral health status

An engineered cardiac reporter cell line identifies human embryonic stem cell-derived myocardial precursors.

Unlike some organs, the heart is unable to repair itself after injury. Human embryonic stem cells (hESCs) grow and divide indefinitely while maintaining the potential to develop into many tissues of the body. As such, they provide an unprecedented opportunity to treat human diseases characterized by tissue loss. We have identified early myocardial precursors derived from hESCs (hMPs) using an α-myosin heavy chain (αMHC)-GFP reporter line. We have demonstrated by immunocytochemistry and quantitative real-time PCR (qPCR) that reporter activation is restricted to hESC-derived cardiomyocytes (CMs) differentiated in vitro, and that hMPs give rise exclusively to muscle in an in vivo teratoma formation assay. We also demonstrate that the reporter does not interfere with hESC genomic stability. Importantly, we show that hMPs give rise to atrial, ventricular and specialized conduction CM subtypes by qPCR and microelectrode array analysis. Expression profiling of hMPs over the course of differentiation implicate Wnt and transforming growth factor-β signaling pathways in CM development. The identification of hMPs using this αMHC-GFP reporter line will provide important insight into the pathways regulating human myocardial development, and may provide a novel therapeutic reagent for the treatment of cardiac disease

4-1BB Ligand Signaling to T Cells Limits T Cell Activation

4-1BB ligand (4-1BBL) and its receptor, 4-1BB, are both induced on T cells after activation, but little is known about the role of 4-1BBL. In this study we show that 4-1BBL can transmit signals that limit T cell effector activity under tolerogenic conditions. Cross-linking 4-1BBL inhibited IL-2 production in vitro, primarily with suboptimal TCR stimulation. Furthermore, naive 4-1BBL-deficient OT-II transgenic T cells displayed a greater conversion to effector T cells in vivo when responding to soluble OVA peptide in wild-type hosts, whereas development of Foxp3(+) regulatory T cells was not altered. A greater number of effector T cells also differentiated from naive wild-type OT-II T cells when transferred into 4-1BB-deficient hosts, suggesting that APC-derived 4-1BB is likely to trigger 4-1BBL. Indeed, effector T cells that could not express 4-1BBL accumulated in larger numbers in vitro when stimulated with 4-1BB-expressing mesenteric lymph node dendritic cells. 4-1BBL was expressed on T cells when Ag presentation was limiting, and 4-1BBL was aberrantly expressed at very high levels on T cells that could not express 4-1BB. Trans-ligation, Ab capture, and endocytosis experiments additionally showed that T cell-intrinsic 4-1BB regulated internalization of membrane 4-1BBL, implying that the strong induction of 4-1BB on T cells may counteract the suppressive function of 4-1BBL by limiting its availability. These data suggest that 4-1BBL expressed on T cells can restrain effector T cell development, creating a more favorable regulatory T cell to effector cell balance under tolerogenic conditions, and this may be particularly active in mucosal barrier tissues where 4-1BB-expressing regulatory dendritic cells present Ag.X11149Ysciescopu

Vaccines for prophylaxis of viral infections in patients with hematological malignancies.

Viral infections cause significant morbidity and mortality in patients with hematological malignancies. It remains uncertain whether viral vaccinations in these patients are supported by good evidence. We aimed to determine the effectiveness and safety of viral vaccines in patients with hematological malignancies. We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL (June 2010), reference lists of relevant papers, abstracts from scientific meetings and contacted vaccine manufacturers. Randomized controlled trials (RCTs) evaluating viral vaccines in patients with hematological malignancies were included. Relative risk (RR) was used for binary data and mean difference (MD) for continuous data. Primary outcome was incidence of infection. Secondary outcomes were mortality, incidence of complications and severe viral infection, hospitalization, immune response and adverse effects. Fixed-effect model was used in meta-analyses. Eight RCTs were included, with 305 patients in the intervention groups and 288 in the control groups. They evaluated heat-inactivated varicella zoster virus (VZV) vaccine (two trials), influenza vaccines (five trials) and inactivated poliovirus vaccine (IPV) (one trial). Seven trials had high and one trial had moderate risk of bias.VZV vaccine might reduce herpes zoster compared to no vaccine (RR 0.54, 95% CI 0.3 to 1.0, P=0.05), but not statistically significant. Vaccination also demonstrated efficacy in immune response but frequently caused local adverse effects. One trial reported severity score of zoster, which favored vaccination (MD 2.6, 95% CI 0.94 to 4.26, P=0.002).Two RCTs compared inactivated influenza vaccine with no vaccine and reported lower risk of lower respiratory infections (RR 0.39, 95% CI 0.19 to 0.78, P=0.008) and hospitalization (RR 0.17, 95% CI 0.09 to 0.31, P<0.00001) in vaccine recipients. However, vaccine recipients more frequently experienced irritability and local adverse effects. There was no significant difference in seroconversion between one and two doses of influenza vaccine (one trial), or between recombinant and standard influenza vaccine (one trial), or influenza vaccine given with or without re-induction chemotherapy (one trial).The IPV trial comparing vaccination starting at 6 versus 18 months after stem cell transplant (SCT) found no significant difference in seroconversion. Inactivated VZV vaccine might reduce zoster severity in adult SCT recipients. Inactivated influenza vaccine might reduce respiratory infections and hospitalization in adults with multiple myeloma or children with leukemia or lymphoma. However, the quality of evidence is low. Local adverse effects occur frequently. Further high-quality RCTs are needed.link_to_subscribed_fulltex

Lycium barbarum (wolfberry) polysaccharide facilitates ejaculatory behaviour in male rats

Poster Session AOBJECTIVE: Lycium barbarum (wolfberry) is a traditional Chinese medicine, which has been considered to have therapeutic effect on male infertility. However, there is a lack of studies support the claims. We thus investigated the effect of Lycium barbarum polysaccharide (LBP), a major component of wolfberry, on male rat copulatory behavior. METHOD: Sprague-Dawley rats were divided into two groups (n=8 for each group). The first group received oral feeding of LBP at dosage of 1mg/kg daily. The control group received vehicle (0.01M phosphate-buffered saline, served as control) feeding daily for 21 days. Copulatory tests were conducted at 7, 14 and 21 days after initiation of treatment. RESULTS: Compared to control animals, animals fed with 1mg/kg LBP showed improved copulatory behavior in terms of: 1. Higher copulatory efficiency (i.e. higher frequency to show intromission rather than mounting during the test), 2. higher ejaculation frequency and 3. Shorter ejaculation latency. The differences were found at all time points (Analyzed with two-tailed student’s t-test, p<0.05). There is no significant difference found between the two groups in terms of mount/intromission latency, which indicates no difference in time required for initiation of sexual activity. Additionally, no difference in mount frequency and intromission frequency was found. CONCLUSION: The present study provides scientific evidence for the traditional use of Lycium barbarum on male sexual behavior. The result provides basis for further study of wolfberry on sexual functioning and its use as an alternative treatment in reproductive medicine.postprintThe 30th Annual Meeting of the Australian Neuroscience Society, in conjunction with the 50th Anniversary Meeting of the Australian Physiological Society (ANS/AuPS 2010), Sydney, Australia, 31 January-3 February 2010. In Abstract Book of ANS/AuPS, 2010, p. 177, abstract no. POS-TUE-19