Project-Based Learning: an Effective Approach to Link Teacher Professional Development and Students Learning

Professional development for teachers is a key mechanism for improving classroom instruction and student achievement, yet there is little empirical evidence upon which to damonstrate the connection between teachers’ professional development and students’ achievement. This paper presents a pilot research which adopts project-based teaching and learning(PjBL) as an approch to link teahcer professional development and student learning. In our longitudinal study, a resource-rich school in urban areas and a less developed school in outlying areas join hands to carry out a research project. Study groups were composed of 2-3 teachers and 10-15 students in each school. The groups from different regions then collaboratively carried out a learning project with the support of an online learning community. The data is collected from focus groups and interviews with stakeholders, online surveys and paper-based questionnaires, computer proficiency tests, observations from site visits, and an analysis of the students\u27 artificial product. Research findings show that project-based collaborative inquiry activity provides the greatest support for teachers and students to develop their comprehensive capacity

Studies on the catalytic mechanism of cytochrome bc1 complex

Scope and Method of Study: The purpose of this study is to further investigate the catalytic mechanism of cytochrome bc1 complexes. With site-directed mutagenesis, we constructed a series of mutant cytochrome bc1 complexes, such as mutants lacking heme bL and bH, mutant in which ISP is fixed at c1-position by engineered inter-subunit disulfide bond, and mutants whose mutations are located in the ef loop of subunit cytochrome b. I have investigated mutant complexes' biochemical and biophysical properties with EPR, stopflow, spectrophotometer, and so on.Findings and Conclusions: In mutant H198N of cytochrome b, no heme bL is formed. Likewise, in mutant H111N, no heme bH is formed. The loss of either heme bL or heme bH will significantly decrease cytochrome c and c1's reduction rates. However, in the mutant H111N, heme bL reduction rate is pretty close to that of wild type bc1. Since heme bL cannot be reduced unless ISP took one electron from QH2, we can conclude that ISP reduction rate in H111N is also close to that of wild type bc1. As a consequence, we can conclude that ISP movement is controlled by the electron transfer in low potential chain. Meanwhile, fast kinetics studies show that antimycin can affect QH2 oxidation at QP Pocket. EPR spectra from these two mutants doesn't show the presence of antimycin-resistant radical signal, indicating QH2 oxidation maybe follows concerted mechanism. Proteinase K digested cytochrome bc1 increases superoxide production, indicating proteinous component in cytochrome bc1 is not required for superoxide production. Further investigation shows that hydrophobic environment and high potential oxidant are required for superoxide production by QH2. Purified Mutant protein S141C(ISP)/G180C(cyt. c1) shows very little catalytic activities. However, after treated with ?-mecaptoethanol, its activities can be recovered up to 80% of that of wild type bc1. Electron transfer rate between ISP and cytochrome c1 in this mutant is 100 times faster than that in wild type bc1, further indicating ISP head domain is fixed at c1-position in this mutant. Two important residues (I192, L286 in the ef loop of R.S. cytochrome bc1 were identified through alanine scanning. Analysis of catalytic activities indicated their bulky side chain plays a role during catalysis. Further investigation is needed

Extend the shallow part of Single Shot MultiBox Detector via Convolutional Neural Network

Single Shot MultiBox Detector (SSD) is one of the fastest algorithms in the current object detection field, which uses fully convolutional neural network to detect all scaled objects in an image. Deconvolutional Single Shot Detector (DSSD) is an approach which introduces more context information by adding the deconvolution module to SSD. And the mean Average Precision (mAP) of DSSD on PASCAL VOC2007 is improved from SSD's 77.5% to 78.6%. Although DSSD obtains higher mAP than SSD by 1.1%, the frames per second (FPS) decreases from 46 to 11.8. In this paper, we propose a single stage end-to-end image detection model called ESSD to overcome this dilemma. Our solution to this problem is to cleverly extend better context information for the shallow layers of the best single stage (e.g. SSD) detectors. Experimental results show that our model can reach 79.4% mAP, which is higher than DSSD and SSD by 0.8 and 1.9 points respectively. Meanwhile, our testing speed is 25 FPS in Titan X GPU which is more than double the original DSSD.Comment: 7 pages, 3 figures, 3 table

Sodium butyrate ameliorates gut dysfunction and motor deficits in a mouse model of Parkinson’s disease by regulating gut microbiota

BackgroundA growing body of evidence showed that gut microbiota dysbiosis might be associated with the pathogenesis of Parkinson’s disease (PD). Microbiota-targeted interventions could play a protective role in PD by regulating the gut microbiota-gut-brain axis. Sodium butyrate (NaB) could improve gut microbiota dysbiosis in PD and other neuropsychiatric disorders. However, the potential mechanism associated with the complex interaction between NaB and gut microbiota-gut-brain communication in PD needs further investigation.MethodsC57BL/6 mice were subjected to a rotenone-induced PD model and were treated intragastrically with NaB for 4 weeks. The gut function and motor function were evaluated. The α-synuclein expression in colon and substantia nigra were detected by western blotting. Tyrosine hydroxylase (TH)-positive neurons in substantia nigra were measured by immunofluorescence. Moreover, gut microbiota composition was analyzed by 16S rRNA sequencing. Fecal short chain fatty acids (SCFAs) levels were determined by liquid chromatography tandem mass spectrometry (LC–MS). The levels of glucagon like peptide-1 (GLP-1) in tissues and serum were evaluated using enzyme-linked immunosorbent assay (ELISA).ResultsNaB ameliorated gut dysfunction and motor deficits in rotenone-induced mice. Meanwhile, NaB protected against rotenone-induced α-synuclein expression in colon and substantia nigra, and prevented the loss of TH-positive neurons. In addition, NaB could remodel gut microbiota composition, and regulate gut SCFAs metabolism, and restore GLP-1 levels in colon, serum, and substantia nigra in PD mice.ConclusionNaB could ameliorate gut dysfunction and motor deficits in rotenone-induced PD mice, and the mechanism might be associated with the regulation of gut microbiota dysbiosis

Shen-Fu Injection Preconditioning Inhibits Myocardial Ischemia-Reperfusion Injury in Diabetic Rats: Activation of eNOS via the PI3K/Akt Pathway

The aim of this paper is to investigate whether Shen-fu injection (SFI), a traditional Chinese medicine, could attenuate myocardial ischemia-reperfusion (MI/R) injury in diabetes. Streptozotocin-induced diabetic rats were randomly assigned to the Sham, I/R, SFI preconditioning, and SFI plus wortmannin (a phosphatidylinositol 3-kinase inhibitor) groups. After the treatment, hearts were subjected to 30 min of coronary artery occlusion and 2 h reperfusion except the Sham group. Myocardial infarct size and cardiomyocytes apoptosis were increased significantly in MI/R group as compared with the Sham group. SFI preconditioning significantly decreased infarct size, apoptosis, caspase-3 protein expression, MDA level in myocardial tissues, and plasma level of CK and LDH but increased p-Akt, p-eNOS, bcl-2 protein expression, and SOD activity compared to I/R group. Moreover, SFI-induced cardioprotection was abolished by wortmannin. We conclude that SFI preconditioning protects diabetic hearts from I/R injury via PI3K/Akt-dependent pathway

Dynamic Carbon Emission Linkages Across Boundaries

Cities are increasingly linked to domestic and foreign markets during rapid globalization of trade. While transboundary carbon footprints of cities have been recently highlighted, we still have limited understanding of how carbon emission linkages between sectors are reshaping urban carbon footprints through time. In this study, we propose an integrated input-output approach to trace the dynamics of various types of carbon emission linkages associated with a city. This approach quantifies full linkages in the urban carbon system from both production- and consumption-based perspectives. We assess the dynamic roles that economic sectors and activities play in manipulating multiscale linkages induced by local, domestic, and international inputs. Using Beijing as a case study, we find that imports from domestic and foreign markets have an increasing impact on the city's carbon footprint with more distant linkages during the period from 1990 to 2012. The manufacturing-related carbon emission linkages have been increasingly transferred outside the urban boundary since 2005, while the linkages from the energy sector to services sectors remain important in Beijing's local economy. Applying systems thinking to input-output linkage analysis provides important details on when and how carbon emission linkages evolved in cities, whereby sector-oriented and activity-oriented carbon mitigation policies can be formulated

The mitochondrial gene orfH79 plays a critical role in impairing both male gametophyte development and root growth in CMS-Honglian rice

<p>Abstract</p> <p>Background</p> <p>Cytoplasmic male sterility (CMS) has often been associated with abnormal mitochondrial open reading frames. The mitochondrial gene <it>orfH79 </it>is a candidate gene for causing the CMS trait in CMS-Honglian (CMS-HL) rice. However, whether the <it>orfH79 </it>expression can actually induce CMS in rice remains unclear.</p> <p>Results</p> <p>Western blot analysis revealed that the ORFH79 protein is mainly present in mitochondria of CMS-HL rice and is absent in the fertile line. To investigate the function of ORFH79 protein in mitochondria, this gene was fused to a mitochondrial transit peptide sequence and used to transform wild type rice, where its expression induced the gametophytic male sterile phenotype. In addition, excessive accumulation of reactive oxygen species (ROS) in the microspore, a reduced ATP/ADP ratio, decreased mitochondrial membrane potential and a lower respiration rate in the transgenic plants were found to be similar to those in CMS-HL rice. Moreover, retarded growth of primary and lateral roots accompanied by abnormal accumulation of ROS in the root tip was observed in both transgenic rice and CMS-HL rice (YTA).</p> <p>Conclusion</p> <p>These results suggest that the expression of <it>orfH79 </it>in mitochondria impairs mitochondrial function, which affects the development of both male gametophytes and the roots of CMS-HL rice.</p