Efficient Network Structures with Separable Heterogeneous Connection Costs

We introduce a heterogeneous connection model for network formation to capture the effect of cost heterogeneity on the structure of efficient networks. In the proposed model, connection costs are assumed to be separable, which means the total connection cost for each agent is uniquely proportional to its degree. For these sets of networks, we provide the analytical solution for the efficient network and discuss stability impli- cations. We show that the efficient network exhibits a core-periphery structure, and for a given density, we find a lower bound for clustering coefficient of the efficient network.Comment: 9 page

On The Robustness of z=0-1 Galaxy Size Measurements Through Model and Non-Parametric Fits

We present the size-stellar mass relations of nearby (z=0.01-0.02) Sloan Digital Sky Survey galaxies, for samples selected by color, morphology, Sersic index n, and specific star formation rate. Several commonly employed size measurement techniques are used, including single Sersic fits, two-component Sersic models, and a non-parametric method. Through simple simulations, we show that the non-parametric and two-component Sersic methods provide the most robust effective radius measurements, while those based on single Sersic profiles are often overestimates, especially for massive red/early-type galaxies. Using our robust sizes, we show for all sub-samples that the mass-size relations are shallow at low stellar masses and steepen above ~ 3-4 x 10^{10}\msun. The mass-size relations for galaxies classified as late-type, low-n, and star-forming are consistent with each other, while blue galaxies follow a somewhat steeper relation. The mass-size relations of early-type, high-n, red, and quiescent galaxies all agree with each other but are somewhat steeper at the high-mass end than previous results. To test potential systematics at high redshift, we artificially redshifted our sample (including surface brightness dimming and degraded resolution) to z=1 and re-fit the galaxies using single Serisc profiles. The sizes of these galaxies before and after redshifting are consistent and we conclude that systematic effects in sizes and the size-mass relation at z ~ 1 are negligible. Interestingly, since the poorer physical resolution at high redshift washes out bright galaxy substructures, single-Sersic fitting appears to provide more reliable and unbiased effective radius measurements at high z than for nearby, well-resolved galaxies.Comment: 18 pages, 15 figures, Accepted for publication in Ap

ANALISIS MATERI, METODE, KENDALA, DAN UPAYA GURU DALAM PEMBELAJARAN MATEMATIKA PADA ANAK TUNAGRAHITA DI SDLB-C PEMBINA TINGKAT NASIONAL MALANG

Anak tunagrahita mempunyai tugas perkembangan yang sama dengan anak “normal” serta mempunyai hak yang sama dalam belajar maupun dalam memperoleh pembelajaran yang baik. Matematika ada dihampir setiap kehidupan kita dari yang sangat sederhana hingga yang sangat kompleks. Pengetahuan matematika akan sangat membantu mereka untuk dapat mandiri dan menyesuaikan diri dengan lingkungannya. Penelitian ini bertujuan mengetahui bagaimana pembelajaran matematika pada anak tunagrahita ringan di SDLB-C SLB PTN Malang. Dari hasil penelitian yang dilakukan mulai tanggal 7-23 November 2011, didapatkan bahwa materi matematika diberikan secara fleksibel dan batasan pada kurikulum tidak mutlak diikuti. Dalam artian materi matematika diberikan sesuai dengan kondisi dan kemampuan anak dalam belajar. Model pembelajaran yang digunakan adalah model pembelajaran tematik dengan menggunakan berbagai variasi metode dan media. Kendala yang dihadapi meliputi: kondisi siswa, orang tua, buku pelajaran, dan kurikulum. Upaya yang dilakukan antara lain: memanfaatkan setiap peluang yang ada untuk mengkondisikan anak pada kondisi belajar; bimbingan yang intensif; pengawasan yang terus-menurus; memberikan motivasi; melakukan penyesuaian dengan anak; memberikan pemahaman kepada orang tua; membuat buka ajar sendiri; menggunakan buku sekolah regular maupun majalah yang disesuaikan dengan kondisi anak; serta melakukan penyederhanaan dan penyesuaian kurikulum. Saran dalam penelitian ini adalah perlu adanya penelitian bersama yang dilakukan oleh beberapa ahli (matematika, PLB, psykolgi). Dengan demikian diharapkan dapat melihat fenomena yang terjadi secara menyeluruh dari berbagai sudut pandang yang saling melengkapi, sehingga mendapatkan deagnosis yang tepat terhadap kelemahan dan kekuatan pembelajaran yang telah dilaksanakan. Dengan demikian diharapkan dapat memberika solusi terbaik dalam melaksankan pembelajaran matematika pada anak tunagrahita

Hepatitis C virus induced changes in cellular lipids - identifying novel host antiviral drug target

Nearly 300,000 Australians and 200 million people throughout the world have been exposed to the hepatitis C virus (HCV). Furthermore, over 10,000 new infections are reported on an annual basis. HCV is associated with chronic disease leading to hepatic fibrosis that may progress to liver failure and cancer, and is a leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma. Hepatitis C virus (HCV) replication is closely linked to lipid metabolism. Therefore, lipidomic analysis of HCV infected hepatic cells can offer insights into the pathogenesis of HCV infection and identify molecular targets that can serve as potential targets for new treatments. Results: HP-TLC showed increased amounts of phosphatidylcoline in lipid extracts from whole cells and from ER fractions of JFH1 infected Huh-7 cells. PC was the only phospholipid species detected in purified lipid droplets, and was significantly increased in infected cells. PYTC1 (CTP:phosphocholine cytidylyltransferase) and PEMT (phosphatidylethanolamine N-methyltransferase) are the rate limiting enzymes of PC biosynthesis in hepatocytes. Silencing PYTC1 had no effect on HCV replication or infectivity. However, when PEMT was silenced, both viral replication and infectivity were decreased by more than 50%, and less lipids accumulation was observed. Conclusion: Our data reveal global changes in lipid abundance, particularly in the ER, which are predicted to impact the HCV life cycle and pathogenesis. We report increased PC content in the ER and in lipid droplets. Our data suggest that in HCV infected cells the minor PC synthesis pathway is most important, as inhibiting PEMT inhibits replication and production of infectious virus

TECHNIQUES IN TEACHING READING COMPREHENSION

Sebagai medium komunikasi dan alat belajar, reading menyajikan sebuah fungsi yang diperlukan dalam masyarakat. Dalam mengajari bahasa, seorang guru harus mempunyai persiapan keprofesionalan secara umum dan ilmu pengetahuan yang khusus di bidang bahasa asing yang dia ajari. Mengetahui bahwa teknik mengajar adalah penting dalam menentukan keberhasilan proses belajar-mengajar, menyajikan materi dengan efektif dan bertujuan. Guru selalu mencoba menggunakan bermacam-macam teknik untuk membantu murid belajar biasa membaca materi English dengan mudah dan dengan banyak mengerti

Investigation of CNT-induced Escherichia coli Lysis and Protein Release

This research investigated the use of carbon nanotubes (CNTs) as a treatment to increase the permeability of a bacterial cell wall. Recombinant Escherichia coli BL21 (DE3) containing a plasmid that expressed Green Fluorescent Protein (GFP) and -lactamase were exposed to CNTs under various levels of agitation for different times. Fluorescence assay for GFP, optical absorbance for -lactamase activity, and Transmission Electron Microscopy (TEM) were used to determine the amount of released protein, and visually examine the permeability enhancement of the cells, respectively. It was found that more -lactamase was present in the culture fluid after treatment with CNTs in a dose dependent manner. Indeed, CNTs can lyse the cells up to 90% of maximum when compared to lysozyme treatment. Based on TEM, it is believed that this treatment damaged the cell walls to make E. coli permeable, causing periplasm proteins and enzymes to leak out into the medium. Consequently, CNTs can be used as lysis agents when it is undesirable to add an additional enzyme (lysozyme) to cause the release of intracellular proteins

The Biomedical and Holistic Practices of the Continuum of Healthism

This MRP critically interrogates the concepts of biomedical healthim and holistic healthism. The existing literature posits that holistic healthism is conceived as the positive solution to the restraints of biomedical healthism. Grounded in an analysis of obesity, the main assertion of the MRP concerns the way in which both forms of healthism are not oppositional, but rather, create a continuum. As such, the MRP argues that both forms of healthism are differing processes which work to foster the same end goal of achieving optimum health. Consequently, the MRP will also argue that healthism is a metaphysical ideal/ethos in which biomedical and holistic paradigms are subsumed under. Situated in neither Health Studies nor Fat Studies, the MRP will consider the implications for a life expressed and finally provide suggestions for an alternative conception to the restrictive lens of healthism