1,066 research outputs found
The Hierarchical Formation of the Galactic Disk
I review the results of recent cosmological simulations of galaxy formation
that highlight the importance of satellite accretion in the formation of
galactic disks. Tidal debris of disrupted satellites may contribute to the disk
component if they are compact enough to survive the decay and circularization
of the orbit as dynamical friction brings the satellite into the disk plane.
This process may add a small but non-negligible fraction of stars to the thin
and thick disks, and reconcile the presence of very old stars with the
protracted merging history expected in a hierarchically clustering universe. I
discuss various lines of evidence which suggest that this process may have been
important during the formation of the Galactic disk.Comment: paper to be read at the "Penetrating Bars through Masks of Cosmic
Dust" conference in South Afric
Analisis Pengaruh Etos Kerja, Hubungan Kerja dan Pengembangan Karir terhadap Komitmen Organisasional Berdampak pada Kinerja Karyawan
Tujuan penelitian ini adalah menganalisis pengaruh etos kerja, hubungan kerja, danpengembangan karir terhadap kinerja karyawan, dengan komitmen organisasional sebagaivariabel intervening. Sumber daya manusia yang baik diperlukan guna mencapai tujuanorganisasi yaitu meningkatkan kinerja untuk mampu bertahan dalam persaingan lingkunganbisnis. Metode yang digunakan dalam penelitian ini adalah metode analisis kuantitatif, denganteknik pengambilan sampel yaitu non-probability sampling – judgment sampling. Data yangdiperoleh kemudian diolah dengan menggunakan metode regresi linear berganda. Hasilpenelitian dari sample 152 responden menunjukkan bahwa etos kerja, hubungan kerja, danpengembangan karir secara parsial berpengaruh signifikan terhadap komitmen organisasional,sedangkan komitmen organisasional berpengaruh signifikan terhadap kinerja. Selanjutnya,komitmen organisasional memediasi pengaruh hubungan kerja dan pengembangan karir terhadapkinerja, namun tidak memediasi etos kerja terhadap kinerja. Namun, etos kerja, hubungan kerja,dan pengembangan karir secara simultan berpengaruh signifikan terhadap kinerja
Tidal Torques and the Orientation of Nearby Disk Galaxies
We use numerical simulations to investigate the orientation of the angular
momentum axis of disk galaxies relative to their surrounding large scale
structure. We find that this is closely related to the spatial configuration at
turnaround of the material destined to form the galaxy, which is often part of
a coherent two-dimensional slab criss-crossed by filaments. The rotation axis
is found to align very well with the intermediate principal axis of the inertia
momentum tensor at this time. This orientation is approximately preserved
during the ensuing collapse, so that the rotation axis of the resulting disk
ends up lying on the plane traced by the protogalactic material at turnaround.
This suggests a tendency for disks to align themselves so that their rotation
axis is perpendicular to the minor axis of the structure defined by surrounding
matter. One example of this trend is provided by our own Galaxy, where the
Galactic plane is almost at right angles with the supergalactic plane (SGP)
drawn by nearby galaxies; indeed, the SGP latitude of the North Galactic Pole
is just 6 degrees. We have searched for a similar signature in catalogs of
nearby disk galaxies, and find a significant excess of edge-on spirals (for
which the orientation of the disk rotation axis may be determined
unambiguously) highly inclined relative to the SGP. This result supports the
view that disk galaxies acquire their angular momentum as a consequence of
early tidal torques acting during the expansion phase of the protogalactic
material.Comment: 5 pages, 2 figures, accepted for publication in ApJ
The effect of group cognitive-behavioral therapy in reducing aggression in patients with thalassemia
The aim of this study was to investigate the effectiveness of cognitive-behavioral therapy (CBT) on aggression in patients with thalassemia.Methods: This is an applied study in terms of objective and it is semi-experimental due to the nature of the subject, pre-test, post-test and follow-up conducted in the control group. The sample consisted of 30 patients with thalassemia city in Bojnourd, they were selected by convenience sampling method and voluntarily participated in the study. The participants were randomly divided into two groups. The first group received cognitive - behavioral therapy and the second group received no therapy. Both groups were assessed by the pre-test, post-test, and one month follow up. The assessment tool in this study were Aggression Questionnaire AGQ. Data were analyzed using SPSS software and variance analysis with repeated measures.Findings: the results showed that there is a significant correlation between the experimental group that received cognitive behavioral therapy and the control group that received no therapy in reducing aggression. These findings have important theoretical and clinical interventions.Conclusion: The results of this study will be to assess and validate detection and more precise controls used in the treatment of aggression in children with thalassemia in clinics. As well as services (CBT) to this group of clinical population as a nonpharmacologic (NMT) are effective.Keywords: cognitive behavioral group therapy, aggression, children with thalassemi
Body fat and risk of cardiovascular diseases among the Tamil school teachers in Kuala Selangor, Selangor
This quantitative survey aims to measure the overall body fat, BMI, abdominal fat and the risk of cardiovascular diseases among 60 Tamil school teachers from Kuala Selangor District, Selangor. The subjects voluntarily participated in this study. The total body fat, Body Mass Index (BMI) and abdominal fat were measured using Omron Karada Scanner, meanwhile PACER test was used to measure cardiovascular endurance. The descriptive analysis showed, 71.67% Tamil school teachers from Kuala Selangor were found to be in the category of excessive body fat and obese. BMI levels, showed that 26.68% were overweight, 48.33% teachers were in level pre-obese till to obese stage III. Abdominal fat levels showed that 70% teachers were at risk. While only 20% of them having good cardiovascular fitness. The inferential analysis showed that there were significant differences in overall body fat and cardiovascular endurance between male and female subjects but BMI and abdominal fat levels showed no significant difference between male and female subjects. The findings indicated that most of the Tamil school teachers in Kuala Selangor District having high risk of cardiovascular diseases. They should do regular physical activity and consume balanced diet to reduce the risk of body fat and obesity which cause the cardiovascular diseases.Keywords: Obesity, abdominal fat, total body fat, cardiovascular endurance & physical activit
LINVIEW: Incremental View Maintenance for Complex Analytical Queries
Many analytics tasks and machine learning problems can be naturally expressed
by iterative linear algebra programs. In this paper, we study the incremental
view maintenance problem for such complex analytical queries. We develop a
framework, called LINVIEW, for capturing deltas of linear algebra programs and
understanding their computational cost. Linear algebra operations tend to cause
an avalanche effect where even very local changes to the input matrices spread
out and infect all of the intermediate results and the final view, causing
incremental view maintenance to lose its performance benefit over
re-evaluation. We develop techniques based on matrix factorizations to contain
such epidemics of change. As a consequence, our techniques make incremental
view maintenance of linear algebra practical and usually substantially cheaper
than re-evaluation. We show, both analytically and experimentally, the
usefulness of these techniques when applied to standard analytics tasks. Our
evaluation demonstrates the efficiency of LINVIEW in generating parallel
incremental programs that outperform re-evaluation techniques by more than an
order of magnitude.Comment: 14 pages, SIGMO
Efektivitas Multivitamin Dan Meniran (Phyllanthus Neruri L.) Dalam Menurunkan Stres Pada Domba Selama Transportasi [Efficacy of Multivitamin and Meniran (Phyllanthus Neruri L.) on Decreasing Stress in Priangan Sheep During Transportation]
Sheep is one of achievable animal protein sources. Therefore, they need to be transported to/in different places to fulfill the demand of mutton. This research was conducted to know the impact of transportation on stress as presented by leucocyte differentiation (N:L ratio). Blood were taken from sheep without stress transportation as a control for 12 hours.In this research, 12 sheep were divided into 3 groups: KP (control with stress),PA (stress with combination multivitamin and meniran - Phyllanthus niruri L.), PB (stress with combination multivitamin).Blood samples were taken at 0 hour (pre-transportation), 4h, 8h, 12h (during transportation) and 24h, 48h, 72h (post-transportation) to observe leucocyte differentiation. The results showed that ratio N:L (as stress indicator) were higher at all time periods during transportation and after the transportation. Sheep as a control group had reached the peak of ratio N:L at 0 h, meanwhile sheep with combination of multivitamin and meniran at 12 h and sheep with multivitamin only at 8. It means that the sheep with combination of multivitamin and meniran treatment was more effective to response the transportation stress
- …