1,487 research outputs found
A graph of dark energy significance on different spatial and mass scales
The current cosmological paradigm sees the formation and evolution of the
cosmic large-scale structure as governed by the gravitational attraction of the
Dark Matter (DM) and the repulsion of the Dark Energy (DE).
We characterize the relative importance of uniform and constant dark energy,
as given by the Lambda term in the standard LCDM cosmology, in galaxy systems
of different scales, from groups to superclusters.
An instructive "Lambda significance graph" is introduced where the matter-DE
density ratio /rho_Lambda for different galaxy systems is plotted
against the radius R. This presents gravitation and DE dominated regions and
shows directly the zero velocity radius, the zero-gravity radius, and the
Einstein-Straus radius for any fixed value of mass.
Example galaxy groups and clusters from the local universe illustrate the use
of the Lambda significance graph. These are generally located deep in the
gravity-dominated region /rho_Lambda > 2, being virialized. Extended
clusters and main bodies of superclusters can reach down near the border line
between gravity-dominated and DE dominated regions /rho_Lambda = 2. The
scale--mass relation from the standard 2-point correlation function intersects
this balance line near the correlation lenght.
The log /rho_Lambda vs. log R diagram is a useful and versatile way to
characterize the dynamical state of systems of galaxies within the Lambda
dominated expanding universe.Comment: 4 pages, 2 figure
Karakter Indeks Pengembangan Gelatin Taut Silang dengan Sukrosa Teroksidasi dan Glutaraldehid
Ikan merupakan salah satu sumber alternatif gelatin halal tetapi memiliki kualitas yang lebih rendah jika dibandingkan dengan gelatin babi. Taut silang dapat menjadi salah satu solusi untuk meningkatkan kualitasnya. Tujuan penelitian adalah mempelajari pengaruh bahan penaut silang terhadap karakter indeks pengembangan. Prosedur dimulai dengan ekstraksi gelatin dari sisik ikan bandeng dengan metode perendaman basa dan asam. Pembuatan gelatin taut silang dengan cara mencampurkan larutan gelatin ikan bandeng 5% sebanyak 50 ml dengan bahan penaut silang dengan konsentrasi bervariasi sebanyak 50 ml. Campuran kemudian diaduk hingga merata dan dikeringkan dalam oven pada suhu 70oC. Penelitian ini menggunakan bahan penaut silang, yaitu sukrosa teroksidasi dan glutaraldehid. Hasil gelatin taut silang diuji karakteristik indeks pengembangannya. Selain itu, juga digunakan sampel gelatin ikan komersial sebagai pembanding. Pembentukan taut silang ditandai dengan Perubahan konsistensi sampel dari larutan menjadi gel. Perubahan konsistensi paling signifikan terlihat pada gelatin taut silang dengan sukrosa teroksidasi dan glutaraldehid. Dari penelitian ini dapat disimpulkan bahwa peningkatan kadar bahan penaut silang menurunkan indeks pengembangan
The Presence of Visual Neglect after Thrombolytic Treatment in Patients with Right Hemisphere Stroke
Visual neglect (VN) is a common consequence of right hemisphere (RH) stroke. The aims of this study were to explore the presence of VN after RH stroke in the patients with (T+) or without (T−) thrombolytic treatment, and to determine whether thrombolysis is a predictor of VN. The study group consisted of 77 RH infarct patients. VN was evaluated with six conventional subtests of the Behavioural Inattention Test (BIT). Stroke severity was assessed using the National Institute of Health Stroke Scale (NIHSS). In the neuropsychological examination, 22% of all RH stroke patients had VN. VN was present in 15% of the patients in the T+ group and in 28% of the patients in the T− group, but the difference was not statistically significant. Despite that, patients in the T− group had a higher risk of VN than patients in the T+ group. Our results suggest that thrombolysis independently predicted absence of VN
Shell-like structures in our cosmic neighbourhood
Signatures of the processes in the early Universe are imprinted in the cosmic
web. Some of them may define shell-like structures characterised by typical
scales. We search for shell-like structures in the distribution of nearby rich
clusters of galaxies drawn from the SDSS DR8. We calculate the distance
distributions between rich clusters of galaxies, and groups and clusters of
various richness, look for the maxima in the distance distributions, and select
candidates of shell-like structures. We analyse the space distribution of
groups and clusters forming shell walls. We find six possible candidates of
shell-like structures, in which galaxy clusters have maxima in the distance
distribution to other galaxy groups and clusters at the distance of about 120
Mpc/h. The rich galaxy cluster A1795, the central cluster of the Bootes
supercluster, has the highest maximum in the distance distribution of other
groups and clusters around them at the distance of about 120 Mpc/h among our
rich cluster sample, and another maximum at the distance of about 240 Mpc/h.
The structures of galaxy systems causing the maxima at 120 Mpc/h form an almost
complete shell of galaxy groups, clusters and superclusters. The richest
systems in the nearby universe, the Sloan Great Wall, the Corona Borealis
supercluster and the Ursa Major supercluster are among them. The probability
that we obtain maxima like this from random distributions is lower than 0.001.
Our results confirm that shell-like structures can be found in the distribution
of nearby galaxies and their systems. The radii of the possible shells are
larger than expected for a BAO shell (approximately 109 Mpc/h versus
approximately 120 Mpc/h), and they are determined by very rich galaxy clusters
and superclusters with high density contrast while BAO shells are barely seen
in the galaxy distribution. We discuss possible consequences of these
differences.Comment: Comments: 9 pages, 10 figures, Astronomy and Astrophysics, in pres
Evaluation of minimal fracture liaison service resource : costs and survival in secondary fracture prevention-a prospective one-year study in South-Finland
Background Fracture liaison service (FLS) is a secondary prevention model for identification of patients at risk for fragility fractures. Aims This study was conducted to evaluate the number and costs of secondary prevention of low-energy fractures in the city of Kouvola in Finland. Methods Women aged >= 45 years and men >= 60 years treated in the emergency department with a low-energy fracture were identified. Laboratory testing, BMI, and DXA scans were performed. Fracture Risk Assessment Tool was used. The direct FLS costs were calculated. Survival was analyzed using univariate and multivariate analysis and the life-table method. Results 525 patients with 570 fractures were identified. The mean age of women was 73.8 years and of men 75.9 years. Most patients sustained wrist (31%), hip (21%) or proximal humerus (12%) fractures. 41.5% of the patients had osteoporosis according to DXA scans. 62% of patients used calcium and vitamin D daily and 38% started anti-osteoporotic medication. Protective factors for survival were: age <80 years, female sex, and S-25OHD concentration of 50-119 nmol/L. Excess mortality was highest among patients with a fracture of the femur. The total annual direct costs of FLS were 1.3% of the costs of all fractures. Discussion Many low-energy fracture types were associated with excess mortality. The use of anti-osteoporotic medication was not optimal. Conclusions FLS increased the catchment of low-energy fracture patients and was inexpensive. However, identification, evaluation and post-fracture assessment of patients should be expedited. Rehabilitation of hip fracture patients needs to be improved.Peer reviewe
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Positive effects of methylphenidate on hyperactivity are moderated by monoaminergic gene variants in children with autism spectrum disorders.
Methylphenidate (MPH) reduces hyperactive-impulsive symptoms common in children with autism spectrum disorders (ASDs), however, response and tolerability varies widely. We hypothesized monoaminergic gene variants may moderate MPH effects in ASD, as in typically developing children with attention-deficit/hyperactivity disorder. Genotype data were available for 64 children with ASD and hyperactivity who were exposed to MPH during a 1-week safety/tolerability lead-in phase and 58 who went on to be randomized to placebo and three doses of MPH during a 4-week blinded, crossover study. Outcome measures included the Clinical Global Impression-Improvement (CGI-I) scale and the Aberrant Behavior Checklist (ABC-hyperactivity index). A total of 14 subjects discontinued the study because of MPH side effects. Subjects were genotyped for variants in DRD1-DRD5, ADRA2A, SLC6A3, SLC6A4, MAOA and MAOB, and COMT. Forty-nine percent of the sample met positive responder criteria. In this modest but relatively homogeneous sample, significant differences by DRD1 (P=0.006), ADRA2A (P<0.02), COMT (P<0.04), DRD3 (P<0.05), DRD4 (P<0.05), SLC6A3 (P<0.05) and SLC6A4 (P<0.05) genotypes were found for responders versus non-responders. Variants in DRD2 (P<0.001) and DRD3 (P<0.04) were associated with tolerability in the 14 subjects who discontinued the trial. For this first MPH pharmacogenetic study in children with ASD, multiple monoaminergic gene variants may help explain individual differences in MPH's efficacy and tolerability
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