31 research outputs found

    Bose-Einstein Condensate Dark Matter Halos confronted with galactic rotation curves

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    We present a comparative confrontation of both the Bose-Einstein Condensate (BEC) and the Navarro-Frenk-White (NFW) dark halo models with galactic rotation curves. We employ 6 High Surface Brightness (HSB), 6 Low Surface Brightness (LSB), and 7 dwarf galaxies with rotation curves falling into two classes. In the first class rotational velocities increase with radius over the observed range.The BEC and NFW models give comparable fits for HSB and LSB galaxies of this type, while for dwarf galaxies the fit is significantly better with the BEC model. In the second class the rotational velocity of HSB and LSB galaxies exhibits long flat plateaus, resulting in better fit with the NFW model for HSB galaxies and comparable fits for LSB galaxies. We conclude that due to its central density cusp avoidance the BEC model fits better dwarf galaxy dark matter distribution. Nevertheless it suffers from sharp cutoff in larger galaxies, where the NFW model performs better. The investigated galaxy sample obeys the Tully-Fisher relation, including the particular characteristics exhibited by dwarf galaxies. In both models the fitting enforces a relation between dark matter parameters: the characteristic density and the corresponding characteristic distance scale with an inverse power.Comment: published versio

    Principal science results from Surveyor 5

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    The area of Mare Tranquillitatis in which Surveyor 5 landed appears to be similar to sites in Oceanus Procellarum. The gross elemental composition of the surface material and its response to a magnet are similar to those of a basalt. The debris layer appears to consist of aggregates of the order of 1 cm in diameter consisting of fine grains and set in a matrix of less-coherent fine grains (most of them 2 to 60 μ in diameter) mixed with some rocky fragments 1 mm and larger. The static bearing strength is less than 10^4 dynes/cm^2 for the upper few millimeters and averages approximately 3 × 10^5 dynes/cm^2 for the upper few centimeters. The evidence suggests that chemical differentiation has occurred in the moon, probably owing to internal heat sources; this is consistent with the hypothesis that the maria are basaltic volcanic flows

    Galactic rotation curves in brane world models

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    In the braneworld scenario the four dimensional effective Einstein equation has extra source terms, which arise from the embedding of the 3-brane in the bulk. These non-local effects, generated by the free gravitational field of the bulk, may provide an explanation for the dynamics of the neutral hydrogen clouds at large distances from the galactic center, which is usually explained by postulating the existence of the dark matter. In the present paper we consider the asymptotic behavior of the galactic rotation curves in the brane world models, and we compare the theoretical results with observations of both High Surface Brightness and Low Surface Brightness galaxies. For the chosen sample of galaxies we determine first the baryonic parameters by fitting the photometric data to the adopted galaxy model; then we test the hypothesis of the Weyl fluid acting as dark matter on the chosen sample of spiral galaxies by fitting the tangential velocity equation of the combined baryonic-Weyl model to the rotation curves. We give an analytical expression for the rotational velocity of a test particle on a stable circular orbit in the exterior region to a galaxy, with Weyl fluid contributions included. The model parameter ranges for which the χ2\chi^2 test provides agreement (within 1σ\sigma confidence level) with observations on the velocity fields of the chosen galaxy sample are then determined. There is a good agreement between the theoretical predictions and observations, showing that extra-dimensional models can be effectively used as a viable alternative to the standard dark matter paradigm.Comment: to be published in MNRAS, 17 pages, 31 figures, version including corrections on the proo

    The artificial intelligence-based model ANORAK improves histopathological grading of lung adenocarcinoma

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    The introduction of the International Association for the Study of Lung Cancer grading system has furthered interest in histopathological grading for risk stratification in lung adenocarcinoma. Complex morphology and high intratumoral heterogeneity present challenges to pathologists, prompting the development of artificial intelligence (AI) methods. Here we developed ANORAK (pyrAmid pooliNg crOss stReam Attention networK), encoding multiresolution inputs with an attention mechanism, to delineate growth patterns from hematoxylin and eosin-stained slides. In 1,372 lung adenocarcinomas across four independent cohorts, AI-based grading was prognostic of disease-free survival, and further assisted pathologists by consistently improving prognostication in stage I tumors. Tumors with discrepant patterns between AI and pathologists had notably higher intratumoral heterogeneity. Furthermore, ANORAK facilitates the morphological and spatial assessment of the acinar pattern, capturing acinus variations with pattern transition. Collectively, our AI method enabled the precision quantification and morphology investigation of growth patterns, reflecting intratumoral histological transitions in lung adenocarcinoma

    Vojta method in the treatment of developmental hip dysplasia – a case report

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    Wojciech Kiebzak,1,2 Arkadiusz Żurawski,2 Michał Dwornik3 1Center for Pediatrics, Regional Hospital in Kielce, Kielce, Poland; 2Department of Physiotherapy, Faculty of Medicine and Health Sciences, Jan Kochanowski University, Kielce, Poland; 3Department of Osteopathic Medicine and Physiotherapy, Medical College of Podkowa Lesna, Podkowa Lesna, Poland Background: Developmental dysplasia of the hip joint is one of the most common congenital defects and often results in functional and structural disorders. Such cases particularly demand optimizing therapeutic effects and maximally reducing the duration of therapy. Purpose: The aim of this case report is to present the therapeutic process in a child with developmental hip dysplasia. Case report: This is a case report of a female child with a birth weight of 2,800 g and an Apgar score of 9 points born to a gravida 3 para 3 mother at 37 weeks. The child was delivered by cesarean section, and the pregnancy was complicated by oligohydramnios. Subluxation of the left hip joint was diagnosed by an orthopedist in the third month of life. The treatment followed was the Vojta method (the first phase of reflex turning and reflex crawling). Results: During the 6 weeks of the Vojta treatment, the left half of the femoral head was centralized, and the process of formation of the hip joint acetabulum was influenced effectively enough to change the acetabulum’s Graff type from the baseline D to IIb after 41 days of treatment. Conclusion: The diagnostic work-up of congenital hip joint dysplasia should involve a physiotherapist who will investigate the child’s neuro­muscular coordination, in addition to a neonatologist and a pediatrician. The therapy for a disorder of hip joint development of neuromotor origin should involve the application of global patterns according to Vojta. Children with congenital dysplasia of the hip joint should commence rehabilitation as early as possible. Keywords: global pattern, neuromuscular coordination, centralization of the the femoral hea

    Analysis of stability levee during different flooding wave stages

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    The stability of levee depends mainly on mechanical and hydromechanical properties of material used for its construction. The structural capacity of a system beyond the expected loads or actual loads is calculated to a variety of different underground structures such as slopes, retaining walls or tunnels. The stability of structure is often expressed by Factor of Stability (FoS) obtained by numerical modeling. In case of the stability analysis of the levee, the flooding process is limited to few scenarios of flooding waves. The first approach of determination of the most significant stages of flooding wave shape can be found in Dwornik et al. (2015). In this paper, the stability of earthen levee for different stages and flooding waves was calculated. Stability of the levee was described using Factor of Safety implemented in Itasca Flac 2D 7.0 software using the strength reduction procedure (Itasca 2011). It is applied by a strength reduction method, which reduces the shear strength of the material to bring the slope to a state of limiting equilibrium. The value of FoS bigger than 1.0 indicate the stable construction, whereas the value less than 1.0 should be interpreted as a possible unstable model (Itasca 2011). Numerical modeling presented in this paper was performed for 17 different schemes of flooding wave. All the schemas were slight modification of the flooding wave considered during the ISMOP project (www.ismop.pl, Mościcki et al. 2014). The analysis was conducted to the flooding wave described by the four stages: water level increasing, durability of the height water level, the pace of water level decreasing and durability of the stage between cycles of successive flooding waves. The increasing of the water level assumed in the numerical modeling varied from 0.1 m to 3.5 m in height. The high water level, assumed as a 3.5 m, was different for the individual scenario. The decreasing water level varied from 3.5 m to 0.1 m preceding the low water level assumed 0.1 m in height. Calculations show that levee is stable for all tested construction stages. The lowest FoS value was obtained after decreasing water level in the reservoir between levees. The slowest pace of decreasing water level was assumed, the higher value of FoS was obtain, which indicated better levee stability. The study was partly financed from the statutory research project No. 11.11.140.613 of the Department of Geoinformatics and Applied Computer Science, AGH University of Science and Technology and by the National Centre for Research and Development (NCBiR) in Poland, project PBS1/B9/18/2013 (no 180535)

    Making documents confirming the quality of aggregates available via electronic means in practice

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    Poddano analizie praktyczną realizację obowiązku wystawiania dokumentów potwierdzających jakość kruszyw (kopii deklaracji właściwości użytkowych oraz oznakowania CE) w dopuszczalnej formie elektronicznej. Pomimo, że od 24 lutego 2014 r. jest to sposób formalnie dopuszczony Rozporządzeniem Delegowanym Komisji (UE) nr 157/2014 z dnia 30 października 2013 r., jego wykorzystanie w praktyce jest w Polsce dalekie od intencji tego aktu. Z analizy zawartości stron internetowych producentów kruszyw zrzeszonych w Polskim Związku Producentów Kruszyw wynika, że przedsiębiorcy preferują zindywidualizowane formy przekazywania dokumentów (papierowe lub elektroniczne w formie mailowej), unikając udostępniania ich na swoich stronach internetowych. Nie koresponduje to z celami ww. rozporządzenia, polegającymi na wykorzystaniu nowych technologii informatycznych, powodujących obniżanie kosztów ponoszonych przez producentów wyrobów budowlanych i cały sektor budowlany.Implementation of the duty to issue documents confirming the quality of aggregates (copies of declarations of performance and the CE marking) in the admissible electronic form has been analyzed. Despite the fact that as at 24 February 2014 this means was formally accepted pursuant to the Commission Delegated Regulation (EU) No. 157/2015 dated 30 October 2013 on the conditions for making a declaration of performance on construction products available on a website (EU OJ L 52 of 21 February 2014, p. 4)), in practice its use in Poland is far from the intentions set forth in the legal act. As follows from the analysis of the websites of aggregate producers who are associated in Polish Aggregates Association PZPK, the producers prefer individualized forms of transmitting documents (paper or electronic by e-mail) and avoid making them available on their websites. This does not correspond with the aims set forth in the said regulation consisting in the use of new IT technologies to cause a reduction of costs incurred by the producers of construction products and by the construction sector as a whole
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