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Wyszukujesz frazę "Roberts, J." wg kryterium: Autor


Wyświetlanie 1-11 z 11
Tytuł:
On the size of approximately convex sets in normed spaces
Autorzy:
Dilworth, S. J.
Howard, Ralph
Roberts, James W.
Powiązania:
https://bibliotekanauki.pl/articles/1206043.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
Let X be a normed space. A set A ⊆ X is approximately convex} if d(ta+(1-t)b,A)≤1 for all a,b ∈ A and t ∈ [0,1]. We prove that every n-dimensional normed space contains approximately convex sets A with $ℋ(A,Co(A))≥log_2n-1$ and $diam(A)≤C√n(ln n)^2$, where ℋ denotes the Hausdorff distance. These estimates are reasonably sharp. For every D>0, we construct worst possible approximately convex sets in C[0,1] such that ℋ(A,Co(A))=(A)=D. Several results pertaining to the Hyers-Ulam stability theorem are also proved.
Źródło:
Studia Mathematica; 2000, 140, 3; 213-241
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large palaeophiid and nigerophiid snakes from Paleogene Trans-Saharan Seaway deposits of Mali
Autorzy:
Mccartney, J.A.
Roberts, E.M.
Tapanila, L.
O`leary, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/20719.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The Paleogene was a time of high diversity for snakes, and was characterized by some of the largest species known to have existed. Among these snakes were pan-Tethyan marine species of Nigerophiidae and Palaeophiidae. The latter family included the largest sea snake, Palaeophis colossaeus, known from the Trans-Saharan Seaway of Mali during the Eocene. This paper describes new material collected from Malian Trans-Saharan Seaway deposits, including additional material of Palaeophis colossaeus, a new, large species of nigerophiid, Amananulam sanogoi gen. et sp. nov., and a medium-sized snake of indeterminate affinities. The material provides new information on the intracolumnar variation of the vertebral column in Palaeophis colossaeus. We estimate the total length of each species by regression of vertebral measurements on body size. Both Palaeophis colossaeus and Amananulam sanogoi gen. et sp. nov. are the largest or among the largest members of their respective clades. The large size of Tethyan snakes may be indicative of higher temperatures in the tropics than are present today.
Źródło:
Acta Palaeontologica Polonica; 2018, 63, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occupational health and metabolic risk factors: A pilot intervention for transport workers
Autorzy:
Naug, Helen L.
Colson, Natalie J.
Kundur, Avinash
Santha Kumar, Abishek
Tucakovic, Lada
Roberts, Michael
Singh, Indu
Powiązania:
https://bibliotekanauki.pl/articles/2177422.pdf
Data publikacji:
2016-05-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
obesity
transport workers
lifestyle education
education interventions
sedentary behavior
metabolic risk
Opis:
Objectives Heavy vehicle transport workers have a high risk of obesity and obesity-related disorders including cardiovascular disease and diabetes. Sedentary nature of their work makes a healthy work and lifestyle balance difficult to achieve. Educational interventions that promote behavioral changes have been shown to be effective in various group settings. The aims of this study were to determine the prevalence of metabolic risk factors among a population of urban bus drivers; to deliver a 3-month educational intervention specifically tailored for the workplace environment of transport workers; and to evaluate the efficacy of the intervention through quantitative measurements and qualitative feedback. Material and Methods Thirty-three bus drivers from depots in south Queensland were recruited for the study. Baseline metabolic data were collected through anthropometric measurements, blood collection and diet/lifestyle questionnaires. Metabolic risk factors that were analyzed included: waist circumference, blood pressure, fasting glucose, blood triglycerides and high density lipoprotein cholesterol (HDL-C). Three interactive seminars were delivered over a 3-month period. At the end of the period, data collection was repeated. Results At the commencement of the study, 35% of the participants exhibited ≥ 3 of the metabolic risk factors that characterize metabolic syndrome. This is higher than the reported prevalence in the general Australian population (22.1%). A total 21 of the 33 participants remained committed to the intervention and provided pre and post intervention data. Of these, 28% (N = 6) showed a decrease in one or more of the risk factors associated with metabolic syndrome. There was a significant increase in the average HDL-C after the intervention. Qualitative feedback indicated that the workers benefited from the program, especially regarding their awareness of the risks associated with their profession. Conclusions This pilot study demonstrates that lifestyle education seminars specifically tailored for the workplace can have an impact on the health behaviors of transport workers.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2016, 29, 4; 573-584
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new mammal from the Turonian–Campanian (Upper Cretaceous) Galula Formation, southwestern Tanzania
Autorzy:
O’Connor, P.M.
Krause, D.W.
Stevens, N.J.
Groenke, J.R.
MacPhee, R.D.E.
Kalthoff, D.C.
Roberts, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/20223.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
We here establish a new mammaliaform genus and species, Galulatherium jenkinsi (Mammalia), from the Upper Cretaceous Galula Formation in the Rukwa Rift Basin of southwestern Tanzania. This represents the first named taxon of a mammaliaform from the entire Late Cretaceous of continental Afro-Arabia, an interval of 34 million years. Preliminary study of the holotypic and only known specimen (a partial dentary) resulted in tentative assignation to the Gondwanatheria, a poorly known, enigmatic clade of Late Cretaceous–Paleogene Gondwanan mammals (Krause et al. 2003). The application of advanced imaging (μCT) and visualization techniques permits a more detailed understanding of key anatomical features of the new taxon. It reveals that the lower dentition consisted of a large, procumbent lower incisor and four cheek teeth, all of which were evergrowing (hypselodont). Importantly, all of the teeth appear devoid of enamel. Comparisons conducted with a range of Mesozoic and selected Cenozoic mammaliaform groups document a number of features (e.g., columnar, enamel-less and evergrowing teeth, with relatively simple occlusal morphology) expressed in Galulatherium that are reminiscent of several distantly related groups, making taxonomic assignment difficult at this time. Herein we retain the provisional referral of Galulatherium (RRBP 02067) to Gondwanatheria; it is most similar to sudamericids such as Lavanify and Bharratherium from the Late Cretaceous of Madagascar and India, respectively, in exhibiting relatively simple, high-crowned, columnar cheek teeth. Other features (e.g., enamel-less dentition) are shared with disparate forms such as the Late Jurassic Fruitafossor and toothed xenarthrans (e.g., sloths), here attributed to convergence. Revised analyses of the depositional context for the holotype place it as having lived sometime between the late Turonian and latest Campanian (roughly 91–72 million years ago). This enhanced geochronological context helps to refine the palaeobiogeographical significance of Galulatherium among Cretaceous mammals in general and those from Gondwanan landmasses specifically.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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