193 research outputs found
Evolution of Universe to the present inert phase
We assume that current state of the Universe can be described by the Inert
Doublet Model, containing two scalar doublets, one of which is responsible for
EWSB and masses of particles and the second one having no couplings to fermions
and being responsible for dark matter. We consider possible evolutions of the
Universe to this state during cooling down of the Universe after inflation. We
found that in the past Universe could pass through phase states having no DM
candidate. In the evolution via such states in addition to a possible EWSB
phase transition (2-nd order) the Universe sustained one 1-st order phase
transition or two phase transitions of the 2-nd order.Comment: 19 pages, 3 figure
Diffuse coronae in cosmological simulations of milky way-sized galaxies
We investigate the properties of halo gas using three cosmological âzoom-inâ simulations of realistic Milky Way-galaxy analogs with varying sub-grid physics. In all three cases, the mass of hot (T > 106 K) halo gas is Ë1% of the host's virial mass. The X-ray luminosity of two of the runs is consistent with observations of the Milky Way, while the third simulation is X-ray bright and resembles more closely a very massive, star-forming spiral. Hot halos extend to 140 kpc from the galactic center and are surrounded by a bubble of warm-hot (T={10}5-{10}6 K) gas that extends to the virial radius. Simulated halos agree well outside 20-30 kpc with the ÎČ-model of Miller & Bregman based on O vii absorption and O viii emission measurements. Warm-hot and hot gas contribute up to 80% of the total gas reservoir, and contain nearly the same amount of baryons as the stellar component. The mass of warm-hot and hot components falls into the range estimated for {L}* galaxies. With key observational constraints on the density of the Milky Way corona being satisfied, we show that concealing of the ubiquitous warm-hot baryons, along with the ejection of just 20%-30% of the diffuse gas out of the potential wells by supernova-driven outflows, can solve the âmissing baryon problem.â The recovered baryon fraction within 3 virial radii is 90% of the universal value. With a characteristic density of Ë10-4 cm-3 at 50-80 kpc, diffuse coronae meet the requirement for fast and complete ram-pressure stripping of the gas reservoirs in dwarf galaxy satellites
SOME CHARACTERISTICS OF ORGANIC SOILS IRRIGATED WITH MUNICIPAL WASTEWATER
ABSTRACT Soil irrigation with wastewater (WW) gives the opportunity to solve the problems of its disposal, final purification or reuse. Many studies have examined mineral soils upon continued WW application. The aim of this paper was to examine the properties of organic soils 3 years after WW application was discontinued. Peat-muck soil planted with Populus spp. or Salix spp., and mineral-muck soil under grasses were irrigated for 4 years with municipal WW at a low (comparable with intensive NPK fertilization) and high WW rate (600 and 1200 mm yearly, respectively). Soils were analysed for organic matter (OM), pH, bulk density (BD), water holding capacity (WHC), P 2 O 5 , Fe 2 O 3 , Al 2 O 3 , MnO, Zn, Pb, Cu, Cr, magnetic susceptibility (MS) and dehydrogenase and catalase activities. The results were compared with control soils which have never received WW. The study showed that only P 2 O 5 , MnO and catalase activity (CA) were significantly affected by former WW application. On average, P 2 O 5 increased by 30 per cent, whereas MnO decreased by 35 per cent with no differences between the two WW rates. CA decreased by 18 per cent at the high WW rate. Most of tested characteristics were determined by soil type. The peat-muck soil showed higher OM, WHC, P 2 O 5 , MnO, Pb and CA than mineral-muck soil and lower BD, MS, Fe 2 O 3 , Al 2 O 3 and Cr. Soil depth influenced Fe 2 O 3 , MnO, Zn, MS and enzyme activities, while basic soil properties (OM, pH, BD, WHC and P 2 O 5 ) were not changed by soil depth. Heavy metals (Zn, Cr, Cu and Pb) were below upper permissible limits
Orexin receptors exert a neuroprotective effect in Alzheimer's disease (AD) via heterodimerization with GPR103
Orexins are neuropeptides that regulate the sleep-wake cycle and feeding behaviour. QRFP is a newly discovered neuropeptide which exerts similar orexigenic activity, thus playing an important role in energy homeostasis and regulation of appetite. The exact expression and signalling characteristics and physiological actions of QRFP and its receptor GPR103 are poorly understood. AlzheimerĂą âŹâą s disease (AD) patients experience increased nocturnal activity, excessive daytime sleepiness, and weight loss. We hypothesised therefore that orexins and QRFP might be implicated in the pathophysiology of AD. We report that the down-regulation of hippocampal orexin receptors (OXRs) and GPR103 particularly in the cornu ammonis (CA) subfield from AD patients suffering from early onset familial AD (EOFAD) and late onset familial AD (LOAD). Using an in vitro model we demonstrate that this downregulation is due to to AÎČ-plaque formation and tau hyper-phosphorylation. Transcriptomics revealed a neuroprotective role for both orexins and QRFP. Finally we provide conclusive evidence using BRET and FRET that OXRs and GPR103 form functional hetero-dimers to exert their effects involving activation of ERK 1/2. Pharmacological intervention directed at the orexigenic system may prove to be an attractive avenue towards the discovery of novel therapeutics for diseases such as AD and improving neuroprotective signalling pathways
Kemampuan Siswa Dalam Menyelesaikan Soal-soal Uraian Terstruktur Pokok Bahasan Teori Kinetik Gas
"> Penelitian ini bertujuan untuk mengetahui (1) kemampuan kognitif yang dilihat dari hasil belajar peserta didik yang kelas XI MAN Model Palangka Raya dalam mengerjakan soal-soal uraian terstruktur pada pokok bahasan Teori Kinetik Gas; dan (2) kesulitan peserta didik dalam mengerjakan soal-soal uraian terstruktur. Penelitian ini menggunakan metode penelitian kuantitatif dalam mengumpulkan datanya. Penelitian ini menggunakan instrumen dalam bentuk soal uraian terstruktur. Hasil uji coba soal uraian terstruktur pada kelas XI IA-1 MAN Model Palangka Raya mendapatkan tingkat validitas rata-rata 0,536 dan tingkat reliabilitas soal 0,539 dengan kategori cukup. Hasil penelitian menunjukkan bahwa: (1) peserta didik yang mampu dan tidak mengalami masalah dalam mengerjakan soal-soal uraian terstruktur berjumlah 18 peserta didik dan 12 peserta didik tidak mampu dan mengalami masalah dalam mengerjakan soal-soal uraian terstruktur. Peserta didik yang mampu mengerjakan soal-soal uraian terstruktur memiliki ketuntasan belajar â„ batas KKM, yaitu 60% (2) kesulitan peserta didik dalam mengerjakan soal-soal uraian terstruktur terdapat pada penyebutan dan penulisan satuan besaran pada jawaban dengan persentase kesulitan 36,7%, penguasaan operasi hitungan denganpersentase kesulitan 31,4% dan penulisan besaran yang ditanya dalam soal dengan persentase kesulitan 28,6%
Relationship Between Nutritional Habits and Hair Calcium Levels in Young Women
The present study was conducted to investigate whether hair calcium levels are related to nutritional habits, selected status parameters, and life-style factors in young women. Eighty-five healthy female students neither pregnant nor lactating, using no hair dyes or permanents were recruited for the study. Food consumption data, including fortified products and dietary supplements were collected with 4-day records. The calcium levels in hair and serum were analyzed by atomic absorption spectroscopy. Serum osteocalcin and the C-terminal telopeptide of type I collagen were assayed by ELISA. The women were divided into four groups according to their total vitamin D and calcium intakes and hair calcium levels. At adequate calcium intake and comparable serum bone biomarker levels, supplemental vitamin D increased the hair calcium levels. On the other hand, at lower than estimated adequate requirement of vitamin D intake the hair calcium levels were comparable in women with low calcium intakes but consuming high amounts of meat products or those whose diets were rich in dairy products, possibly due to homeostatic mechanisms. Elevated hair calcium was seen in 25% of subjects and could not be related to nutritional or life-style factors. The results show that the hair calcium levels were weakly related to the quality of diet, with some synergistic interactions between nutrients, especially vitamin D and magnesium
The Baryonic Collapse Efficiency of Galaxy Groups in the RESOLVE and ECO Surveys
We examine the z = 0 group-integrated stellar and cold baryonic (stars + cold atomic gas) mass functions (group SMF and CBMF) and the baryonic collapse efficiency (group cold baryonic to dark matter halo mass ratio) using the RESOLVE and ECO survey galaxy group catalogs and a galform semi-analytic model (SAM) mock catalog. The group SMF and CBMF fall off more steeply at high masses and rise with a shallower low-mass slope than the theoretical halo mass function (HMF). The transition occurs at group-integrated cold baryonic mass M_coldbary ~ 10^11 Msun. The SAM, however, has significantly fewer groups at the transition mass ~ 10^11 Msun and a steeper low-mass slope than the data, suggesting that feedback is too weak in low-mass halos and conversely too strong near the transition mass. Using literature prescriptions to include hot halo gas and potential unobservable galaxy gas produces a group BMF with slope similar to the HMF even below the transition mass. Its normalization is lower by a factor of ~2, in agreement with estimates of warm-hot gas making up the remaining difference. We compute baryonic collapse efficiency with the halo mass calculated two ways, via halo abundance matching (HAM) and via dynamics (extended all the way to three-galaxy groups using stacking). Using HAM, we find that baryonic collapse efficiencies reach a flat maximum for groups across the halo mass range of M_halo ~ 10^11.4-12 Msun, which we label "nascent groups." Using dynamics, however, we find greater scatter in baryonic collapse efficiencies, likely indicating variation in group hot-to-cold baryon ratios. Similarly, we see higher scatter in baryonic collapse efficiencies in the SAM when using its true groups and their group halo masses as opposed to friends-of-friends groups and HAM masses
Angular Momentum of Early- and Late-type Galaxies: Nature or Nurture?
We investigate the origin, the shape, the scatter, and the cosmic evolution
in the observed relationship between specific angular momentum and
the stellar mass in early-type (ETGs) and late-type galaxies (LTGs).
Specifically, we exploit the observed star-formation efficiency and chemical
abundance to infer the fraction f_\rm inf of baryons that infall toward the
central regions of galaxies where star formation can occur. We find f_\rm
inf\approx 1 for LTGs and for ETGs with an uncertainty of about
dex, consistent with a biased collapse. By comparing with the locally
observed vs. relations for LTGs and ETGs we estimate the
fraction of the initial specific angular momentum associated to the
infalling gas that is retained in the stellar component: for LTGs we find
, in line with the classic disc formation
picture; for ETGs we infer , that can be
traced back to a evolution via dry mergers. We also show that the
observed scatter in the vs. relation for both galaxy
types is mainly contributed by the intrinsic dispersion in the spin parameters
of the host dark matter halo. The biased collapse plus mergers scenario implies
that the specific angular momentum in the stellar components of ETG progenitors
at is already close to the local values, in pleasing agreement with
observations. All in all, we argue such a behavior to be imprinted by nature
and not nurtured substantially by the environment
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