A refined sub-grid model for black hole accretion and AGN feedback in large cosmological simulations

In large scale cosmological hydrodynamic simulations simplified sub-grid models for gas accretion onto black holes and AGN feedback are commonly used. Such models typically depend on various free parameters, which are not well constrained. We present a new advanced model containing a more detailed description of AGN feedback, where those parameters reflect the results of recent observations. The model takes the dependency of these parameters on the black hole properties into account and describes a continuous transition between the feedback processes acting in the so-called radio-mode and quasar-mode. In addition, we implement a more detailed description of the accretion of gas onto black holes by distinguishing between hot and cold gas accretion. Our new implementations prevent black holes from gaining too much mass, particularly at low redshifts so that our simulations are now very successful in reproducing the observed present-day black hole mass function. Our new model also suppresses star formation in massive galaxies slightly more efficiently than many state-of-the-art models. Therefore, the simulations that include our new implementations produce a more realistic population of quiescent and star-forming galaxies compared to recent observations, even if some discrepancies remain. In addition, the baryon conversion efficiencies in our simulation are - except for the high mass end - consistent with observations presented in literature over the mass range resolved by our simulations. Finally, we discuss the significant impact of the feedback model on the low-luminous end of the AGN luminosity function.Comment: 25 pages, 19 figures. MNRAS accepted. Magneticum website: http://www.magneticum.or

Upaya Peningkatan Keaktifan Belajar Ekonomi Melalui Penggunaan Metode Discovery Learning Pada Siswa Kelas X 2 Sma Negeri 1 Polanharjo Tahun Ajaran 2015/2016

Class Action Research aims to improve students' learning activeness on economic subjects through a learning model Discovery Learning (Invention). The research subject is class X 2 SMA Negeri 1 Polanharjoyang totaled 18 students. Data collection methods used were observation, interviews, field notes and documentation. To ensure the validity of data used triangulation techniques. Data analysis technique used consisted of data reduction, data presentation and verification of data. The results showed an increase in the activity of students in the learning economy through the application of learning models Discovery Learning (Invention). It can be seen from 1) activity of students participating in performing the task of learning before the action amounted to 33.33% and after the action to be 100%. 2) Students who engage in problem solving before the action amounted to 27.77% and to 83.33% after the action. 3) Students who dared to ask other students or teachers before actions 22.22% and amounted to 66.66% after the action. 4) Students are trying to find the information needed to solve the problem before the action amounted to 27.77% and amounted to 61.11% after the action. 5) Students who carry out the corresponding command group discussions teacher before action by 16.66% and amounted to 55.55% after the action. 6) students assess her abilities and the results obtained prior to action by 11.11% and after action by 50%. From the research results support the hypothesis "if the learning economy through the application of learning models Discovery Learning is done properly and appropriately, it can enhance the activity of students in the learning economy"

Understanding Perceptions about Contraceptive Responsibility Among Adolescents

Invited Commentary on Attitudes Surrounding Contraceptive Responsibility: Do Latino Adolescents Differ From Other Groups

Origin and properties of dual and offset active galactic nuclei in a cosmological simulation at z=2

In the last few years, it became possible to observationally resolve galaxies with two distinct nuclei in their centre. For separations smaller than 10kpc, dual and offset active galactic nuclei (AGN) are distinguished: in dual AGN, both nuclei are active, whereas in offset AGN only one nucleus is active. To study the origin of such AGN pairs, we employ a cosmological, hydrodynamic simulation with a large volume of (182Mpc)^3 from the set of Magneticum Pathfinder Simulations. The simulation self-consistently produces 35 resolved black hole (BH) pairs at redshift z=2, with a comoving distance smaller than 10kpc. 14 of them are offset AGN and nine are dual AGN, resulting in a fraction of (1.2 \pm 0.3)% AGN pairs with respect to the total number of AGN. In this paper, we discuss fundamental differences between the BH and galaxy properties of dual AGN, offset AGN and inactive BH pairs and investigate their different triggering mechanisms. We find that in dual AGN the BHs have similar masses and the corresponding BH from the less massive progenitor galaxy always accretes with a higher Eddington ratio. In contrast, in offset AGN the active BH is typically more massive than its non-active counterpart. Furthermore, dual AGN in general accrete more gas from the intergalactic medium than offset AGN and non-active BH pairs. This highlights that merger events, particularly minor mergers, do not necessarily lead to strong gas inflows and thus, do not always drive strong nuclear activity.Comment: 17 pages, 18 figures, accepted for publication in MNRAS, website: http://www.magneticum.or

PENGARUH SERVICE QUALITY, SATISFACTION, STICKINESS, DAN USAGE INTENTION PADA PENGGUNAAN APLIKASI WHATSAPP DI SURABAYA

The purpose of this research is to understand and analyze the influenceof service quality, satisfaction, stickiness toward usage intentionon the application of WhatsApp in Surabaya. Data processing was conducted using software SPSS AMOS 20. The sampling technique thatused is non-probability sampling. 150 respondents, who qualify the specified characteristics of the population were the total of sample used in this research whichdistributed by off line quetionaire. The result of this research that there was a positive influence betweenenvironment quality on satisfaction, a positive influence between outcome quality on satisfaction, a positive influence between satisfaction on usage intention, a positive influence between satisfaction on stickiness, a positive influence between stickiness on usage intention and mediating role of stickiness between satisfaction and usage intention is confirmed

Possible role of membrane gamma-glutamyltransferase activity in the facilitation of transferrin-dependent and -independent iron uptake by cancer cells.

BACKGROUND: The molecular mechanisms by which iron is physiologically transported trough the cellular membranes are still only partially understood. Several studies indicate that a reduction step of ferric iron to ferrous is necessary, both in the case of transferrin-mediated and transferrin-independent iron uptake. Recent studies from our laboratory described gamma-glutamyltransferase activity (GGT) as a factor capable to effect iron reduction in the cell microenvironment. GGT is located on the outer aspect of plasma membrane of most cell types, and is often expressed at high levels in malignant tumors and their metastases. The present study was aimed at verifying the possibility that GGT-mediated iron reduction may participate in the process of cellular iron uptake. RESULTS: Four distinct human tumor cell lines, exhibiting different levels of GGT activity, were studied. The uptake of transferrin-bound iron was investigated by using (55)Fe-loaded transferrin, as well as by monitoring fluorimetrically the intracellular iron levels in calcein-preloaded cells. Transferrin-independent iron uptake was investigated using (55)Fe complexed by nitrilotriacetic acid ((55)Fe-NTA complex). The stimulation of GGT activity, by administration to cells of the substrates glutathione and glycyl-glycine, was generally reflected in a facilitation of transferrin-bound iron uptake. The extent of such facilitation was correlated with the intrinsic levels of the enzyme present in each cell line. Accordingly, inhibition of GGT activity by means of two independent inhibitors, acivicin and serine/boric acid complex, resulted in a decreased uptake of transferrin-bound iron. With Fe-NTA complex, the inhibitory effect – but not the stimulatory one – was also observed. CONCLUSION: It is concluded that membrane GGT can represent a facilitating factor in iron uptake by GGT-expressing cancer cells, thus providing them with a selective growth advantage over clones that do not possess the enzyme

Role of the protein annexin A1 on the efficacy of anti-TNF treatment in a murine model of acute colitis

TNF-α is involved in the mechanisms that initiate inflammatory bowel diseases (IBDs). Anti-TNF-α drugs, such as infliximab (IFX), cause non-responsiveness and side effects, indicating the need to investigate alternative therapies for these diseases. The anti-inflammatory protein, annexin A1 (AnxA1), has been associated with the protection of the gastrointestinal mucosa. To further address the role of endogenous AnxA1 on the TNF-α blockade efficacy in a murine model, we assessed colitis induced by Dextran Sulfate Sodium (DSS) in wild-type (WT) and AnxA1−/− Balb/c mice treated with IFX. We consistently observed endogenous AnxA1 prevented clinical and physiological manifestations of experimental colitis treated with IFX, additionally the manifestation of the disease was observed earlier in AnxA1−/− mice. Rectal bleeding, diarrhea, histological score, epithelial damages and collagen degradation caused by DSS were prevented following IFX treatment only in WT mice. IL-6 increased during colitis in WT and AnxA1−/− mice, decreasing under IFX treatment in WT. The influx of neutrophils and TNF-α secretion were largely elevated in AnxA1−/− mice when compared to WT mice. In the group WT/DSS + IFX, phagocytes were more susceptible to apoptosis following treatment with IFX. Endogenous expression of AnxA1 increased after DSS and decreased with IFX treatment, demonstrating an attenuated inflammatory response. The data indicate that AnxA1 contributes to the establishment of intestinal homeostasis after blocking of TNF-α was used as a treatment of IBD, constituting a key molecule in the mechanism of action and a potential biomarker of therapeutic efficacy.Fil: De Paula Silva, Marina. Universidade de Sao Paulo; BrasilFil: Barrios, Bibiana Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Maccio Maretto, Lisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Sena, Angela. Universidade de Sao Paulo; BrasilFil: Poliselli Farsky, Sandra Helena. Universidade de Sao Paulo; BrasilFil: Correa, Silvia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Oliani, Sonia María. Universidade de Sao Paulo; Brasi

PENGARUH KEUNGGULAN BERSAING, ORIENTASI KEWIRAUSAHAAN TERHADAP KINERJA USAHA RENDANG DI KOTA PAYAKUMBUH

Penelitian ini meneliti tentang keunggulan bersaing, orientasi kewirausahaan terhadap kinerja usaha pada usaha rendang di Kota Payakumbuh. Tujuan penelitian ini adalah untuk 1) menganalisis pengaruh orientasi kewirausahaan terhadap keunggulan bersaing, 2) menganalisis pengaruh orientasi kewiraushaan terhdap kinerja usaha, 3) menganalisis keunggulan bersaing terhadap kinerja usaha, 4) menganalisis keunggulan bersaing memediasi orientasi kewirausahaan terhadap kinerja usaha. Ukuran sampel adalah 38 responden. Teknik pengambilan sampel yaitu dengan metode sampel jenuh dimana seluruh populasi dijadikan sampel. Alat analisis yang digunakan adalah Structural Equation Modelling (SEM) dengan alat bantu software SmartPLS 2.0. Hasil penelitian menunjukan keunggulan bersaing berpengaruh positif terhadap orientasi kewirusahaan, orientasi kewirausahaan berpengaruh pesitif terhadap kinerja usaha, keunggulan bersaing berpengaruh positif terhadap kinerja usaha dan keunggulan bersaing memediasi orientasi kewirausahaan terhadap kinerja usaha. Implikasi penelitian ini, pelaku usaha rendang harus meningkatkan orientasi kewirausahaan yang dapat dilakukan dengan meningkatkan keberanian dalam mengambil resiko dalam memperkenalkan dan memperluas pangsa pasar dengan melihat peluang potensial pada pasar yang belum dituju, meningkatkan keunggulan bersaing dengan memiliki kualitas dan harga produk yang bersaing dan pelaku usaha rendang harus mengikuti pelatihan – pelatihan maupun kursus sehingga lebih terampil dalam menjalankan usaha. Kata Kunci: Keunggulan Bersaing, Orintasi Kewirausahaan, Kinerja Usah