1,867 research outputs found
Combinatorial aspects of nodal curves
To any nodal curve is associated the degree class group, a combinatorial
invariant which plays an important role in the compactification of the
generalised Jacobian of and in the construction of the N\'eron model of the
Picard variety of families of curves having as special fibre. In this paper
we study this invariant. More precisely, we construct a wide family of graphs
having cyclic degree class group and we provide a recursive formula for the
cardinality of the degree class group of the members of this family. Moreover,
we analyse the behaviour of the degree class group under standard geometrical
operations on the curve, such as the blow up and the normalisation of a node.Comment: 28 pages, to appear in Le Matematiche. Revised version: minor
changes, references adde
Temperature enhanced effects of ozone on cardiovascular mortality in 95 large US communities, 1987-2000 - assessment using the NMMAPS data
A few studies examined interactive effects between air pollution and temperature on health outcomes. This study is to examine if temperature modified effects of ozone and cardiovascular mortality in 95 large US cities. A nonparametric and a parametric regression models were separately used to explore interactive effects of temperature and ozone on cardiovascular mortality during May and October, 1987-2000. A Bayesian meta-analysis was used to pool estimates. Both models illustrate that temperature enhanced the ozone effects on mortality in the northern region, but obviously in the southern region. A 10-ppb increment in ozone was associated with 0.41 % (95% posterior interval (PI): -0.19 %, 0.93 %), 0.27 % (95% PI: -0.44 %, 0.87 %) and 1.68 % (95% PI: 0.07 %, 3.26 %) increases in daily cardiovascular mortality corresponding to low, moderate and high levels of temperature, respectively. We concluded that temperature modified effects of ozone, particularly in the northern region
Analisis Tingkat Kinerja Guru Tetap Yayasan Dan Guru Tidak Tetap Di Smk Swasta Se-kota Malang
This study is based on the differences in rights received from permanent teacher and non-permanent teacher, such like teaching hours, benefits received, certification rights from government, and other incentives. So based on the background, the purpose of this research to identify and analyze differences in performance level of permanent teachers and non-permanent teachers at The Private Vocational High School in Malang City. The population on this research is all of Private Vocational High School in Malang City which amounted to 40 schools. The sample of this research is 10 schools, which each school will be represented by 5 permanent teachers and 5 non-permanent teachers. The total of each sample are 50 permanent teachers and 50 non-permanent teachers. This research uses questionnaire and quick interview method. This research’s data analysis is Chi-square statistics. The results showed that there was no difference in performance between permanent teacher and non-permanent teacher on Private Vocational High School in Malang City.Penelitian ini berlatar belakang dari adanya perbedaan hak yang diterima dari Guru Tetap Yayasan (GTY) dan Guru Tidak Tetap (GTT), mulai dari jam mengajar, tunjangan yang diterima, hak mengikuti sertifikasi, dan insentif lainnya. Berdasarkan kondisi tersebut, penelitian ini bertujuan untuk mengidentifikasi dan menganalisis perbedaan tingkat kinerja para GTY dan GTT di SMK Swasta se-Kota Malang. Populasi dalam penelitian ini adalah seluruh SMK Swasta se-Kota Malang yang berjumlah 40 sekolah. Sampel dari penelitian ini adalah 10 sekolah, masing-masing sekolah akan diwakili 5 GTY dan 5 GTT sehingga total masing-masing sampel adalah 50 GTY dan 50 GTT. Penelitian ini menggunakan teknik pengumpulan data kuesioner dan wawancara singkat dengan informan. Analisis data dalam penelitian ini menggunakan teknik statistik Chi-square. Hasil Penelitian menunjukan bahwa tidak ada perbedaan kinerja antara GTY dan GTT di SMK Swasta se-Kota Malang
Probing Wolf-Rayet Winds: Chandra/HETG X-Ray Spectra of WR 6
With a deep Chandra/HETGS exposure of WR 6, we have resolved emission lines
whose profiles show that the X-rays originate from a uniformly expanding
spherical wind of high X-ray-continuum optical depth. The presence of strong
helium-like forbidden lines places the source of X-ray emission at tens to
hundreds of stellar radii from the photosphere. Variability was present in
X-rays and simultaneous optical photometry, but neither were correlated with
the known period of the system or with each other. An enhanced abundance of
sodium revealed nuclear processed material, a quantity related to the
evolutionary state of the star. The characterization of the extent and nature
of the hot plasma in WR 6 will help to pave the way to a more fundamental
theoretical understanding of the winds and evolution of massive stars.Comment: Accepted by the Astrophysical Journa
Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.
he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield
Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth and gene expression patterns and induced resistance to plant pathogens. These compounds may represent novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-homoserine lactone (C6-HSL) impacted winter wheat (Triticum aestivum L.) seed germination, plant development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015-16 and 2016-17) also demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop structure and productivity at maturity including grain yield (1.4 – 1.5x increase, p < 0.0007) and quality (1.3x increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress
Website as Co-Created Decision Support System Towards Enhanced Experience of Solo City Tourism
. The linkage among information-intensive era, technology, and tourism industry build inseparable genetic relationship which is supposed to be realized in practice. Let alone in this digital era, the urgency to exploit information to the next level resulted in the need to bring a higher game on the technology in order to manage information effectively and efficiently. Tourism industry is categorized as complex system regarding the components substituted it. The diverse elements which interact with dynamics pace give birth to complex tasks to manage by the responsible parties and consequently enhance experience in tourism industry. Competing with complex situation, computerized decision system is urgently needed to collect and also distribute accurate knowledge of tourism industry, collaborate with both supporting public and private sectors, and gain rationality for all stakeholders in the system. Solo city, known also as Surakarta and located in Central Java (Indonesia), is obliged to do its tourism industry justice as it is an important vehicle for regional development of the city. Tourism industry of Solo city represents the major and significant contributor to the local economy to the point where tourism is the brand of Solo city. Taking the prior research finding, value orchestration platform to promote tourism in batik Solo industrial cluster into the reference, this study improves the model by highlighting the duality function the tourism website supposed to have using hashtag (#) minings principle as the latest user interface technology. This study proposes a collaborative website platform as a co-created decision support system to enhance tourism experience for tourist as consumer and optimize management process for Department of Culture and Tourism of Solo city as provider
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