The value of pi

1963 ◽  
Vol 10 (2) ◽  
pp. 100
Author(s):  
Ann Setzekorn
Keyword(s):  
Eighth Grade ◽  
Mathematics Textbooks ◽  
The Past ◽  
Large Size ◽  
Basketball Court

Most seventh- and eighth-grade mathematics textbooks suggest that the pupils measure the circumference and diameter of such objects as waste baskets, pie pans, and funnels; and that from these measurements they compute an approximate value for pi. For the past several years we have been using the large circles on the basketball court in our gymnasium. We find a decided advantage in the rather large size of the circles.

Empires Versus States

2017 ◽  
Author(s):  
Josep M. Colomer
Keyword(s):  
United States ◽  
European Union ◽  
United States Of America ◽  
The European Union ◽  
The Past ◽  
Large Size ◽  
Analytical Category

The classical analytical category of “empire,” as opposed to “state,” “city,” “federation,” and other political forms, can account for a large number of historical and current experiences, including the past United States of America, the European Union, Russia, and China. An “empire” has been conceived, in contrast to a “state,” as a very large size polity with a government formed on movable frontiers, with multiple institutional levels, overlapping jurisdictions, and asymmetric relations between the center and the diverse territorial units.

scholarly journals How Dietary Factors Affect DNA Methylation: Lesson from Epidemiological Studies

Medicina ◽  
2020 ◽  
Vol 56 (8) ◽  
pp. 374 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta
Keyword(s):  
Dna Methylation ◽  
Epidemiological Studies ◽  
Dietary Factors ◽  
Negative Effects ◽  
Cross Sectional ◽  
The Past ◽  
Large Size ◽  
Future Challenges ◽  
Public Health Strategies ◽  
The Relationship

Over the past decades, DNA methylation has been proposed as a molecular mechanism underlying the positive or negative effects of diet on human health. Despite the number of studies on this topic is rapidly increasing, the relationship between dietary factors, changes in DNA methylation and health outcomes remains unclear. In this review, we summarize the literature from observational studies (cross-sectional, retrospective, or prospective) which examined the association of dietary factors (nutrients, foods, and dietary patterns) with DNA methylation markers among diseased or healthy people during the lifetime. Next, we discuss the methodological pitfalls by examining strengths and limitations of published studies. Finally, we close with a discussion on future challenges of this field of research, raising the need for large-size prospective studies evaluating the association between diet and DNA methylation in health and diseases for appropriate public health strategies.

scholarly journals XI.—On a Small Collection of Terrestrial Isopoda from Spain, with Descriptions of Four New Species.

1917 ◽  
Vol 51 (2) ◽  
pp. 461-465
Author(s):  
Walter E. Collinge
Keyword(s):  
New Species ◽  
Cambridge University ◽  
The Past ◽  
Large Size ◽  
Present Collection ◽  
Small Collection ◽  
University Museum

I am indebted to the kindness of Dr Leonard Doncaster, F.R.S., for the opportunity to examine the present collection of Terrestrial Isopoda from the Cambridge University Museum of Zoology.The Terrestrial Isopoda of Spain have received considerable attention in the past at the hands of L. Koch,* Budde-Lund,† O. De Buen,‡ and Dollfus,§ and present many features of great interest, one of the most striking of which is perhaps the large size of the various species, particularly in the genera Porcellio, Latreille, and Armadillidium, Brandt, and to these I am now able to add the genus Cubaris, Brandt.

Statistics in the Classroom: Written Projects Portraying Real-World Situations

1992 ◽  
Vol 85 (4) ◽  
pp. 310-313
Author(s):  
Jonita Sommers
Keyword(s):  
Higher Education ◽  
High School ◽  
Real World ◽  
Oil Fields ◽  
Eighth Grade ◽  
The Real ◽  
The Past ◽  
Mathematics Class ◽  
Out Of School

“Why do I have to do this math? This is not something I need to know. I will not use it when I get out of school!” exclaimed Jesse and some of his classmates. Have you ever heard these comments? In the past, my students were learning the concepts, hut they were not associating the importance of mathematics and its uses in the real world. This year, I have tried to show the students in my eighth-grade mathematics class how mathematics will apply to their lives, whether they work on a ranch, work in the oil fields, or get a higher education after high school.

WOOD IDENTIFICATION IN THE CAPPELLA PALATINA CEILING (12th CENTURY) IN PALERMO (SICILY, ITALY)

IAWA Journal ◽  
2007 ◽  
Vol 28 (2) ◽  
pp. 109-124 ◽  
Author(s):  
M. Romagnolj ◽  
M. Sarlatto ◽  
F. Terranova ◽  
E. Bizzarrj ◽  
S. Cesettj
Keyword(s):  
Selection Criteria ◽  
Wood Quality ◽  
Wood Identification ◽  
Anatomical Studies ◽  
The Past ◽  
Large Size ◽  
12Th Century ◽  
Natural Reserve ◽  
Original Tree ◽  
Choice Of Species

Anatomical studies were made on the structural and decorative elements of the wooden ceiling of the 12th century Cappella Palatina in Palermo, Sicily, to identify the timbers used, analyse their likely provenance, and discuss the selection criteria used by the builders. One hundred and fifty fragments were examined. Abies sp., Pinus sp., Betula sp., Populus sp. and Fagus sylvatica were found and all are most probably from Sicily. Some of the Abies fragments probably belong to Abies nebrodensis as they have exceptionally long tracheids, very tall rays, and abundant crystals. This species was over-Iogged in the past and now only 29 trees remain in the Madonie Natural Reserve in Sicily. Abies and Pinus are found in vertieal and horizontal painted panels, while Populus, Betula and Fagus were used in smaller parts of the muqarnas (painted niches). The choice of species seems to have been related to original tree size. The large size of the Abies boles meant that quarter sawn panels could be used. Sieilian Abies was highly valued at that time for its wood quality.Special attention was paid to the problem of distinguishing partly degraded Abies and Cedrus woods. However, the scalloped torus in some sampies displayed ambiguous features and these sampies were therefore classified as Abies/Cedrus.

scholarly journals Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics

2017 ◽  
Vol 284 (1855) ◽  
pp. 20170546 ◽  
Author(s):  
Graham J. Slater ◽  
Jeremy A. Goldbogen ◽  
Nicholas D. Pyenson
Keyword(s):  
Body Size ◽  
Evolutionary Dynamics ◽  
Niche Partitioning ◽  
Ocean Dynamics ◽  
Baleen Whales ◽  
The Past ◽  
Large Size ◽  
Size Evolution ◽  
Primary Determinant ◽  
Quantitative Examination

Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the evolution of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary dynamics in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size evolution during the Plio-Pleistocene. This transition, from Brownian motion-like dynamics to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-driven upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean dynamics may have provided an ecological pathway to gigantism in multiple independent lineages.

scholarly journals Giant cold satellites from low-concentration haloes

2019 ◽  
Vol 489 (1) ◽  
pp. L22-L27
Author(s):  
Nicola C Amorisco
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Velocity Dispersion ◽  
Rare Occurrence ◽  
Low Velocity ◽  
Dynamical Mass ◽  
The Past ◽  
Large Size ◽  
Identify Formation ◽  
Tidal Heating

ABSTRACT The dwarf satellite galaxies of the Milky Way Crater II and Antlia II have uncommonly low dynamical mass densities, due to their large size and low velocity dispersion. Previous work have found it difficult to identify formation scenarios within the Λ cold dark matter (ΛCDM) framework and have invoked cored dark matter haloes, processed by tides. I show that the tidal evolution of ΛCDM NFW haloes is richer than previously recognized. In haloes that fall short of the mass–concentration relation, tidal heating causes the innermost regions to expand significantly, resulting in the formation of giant, kinematically cold satellites like Crater II and Antlia II. While these satellites are reaching apocentre, extra-tidal material can cause an even more inflated appearance. If originally underconcentrated, Crater II and Antlia II may well have experienced very little mass loss, as in fact hinted by their observed metallicity. On a cosmological scale, satellites with low dynamical mass densities are not a rare occurrence, but were more frequent in the past. If indeed a satellite of NGC 1052, the same mechanism may similarly have led to the formation of NGC 1052-DF2.

Black Jack

1978 ◽  
Vol 25 (5) ◽  
pp. 52
Author(s):  
Marie Molinoski
Keyword(s):  
Eighth Grade ◽  
Card Game ◽  
Negative Numbers ◽  
The Past ◽  
Card Games ◽  
Eighth Grade Students ◽  
Basic Concepts

Everyone enjoys games, and games can be an enjoyable and meaningful way to reinforce basic concepts or provide drill in a way that is not boring. During the past few years I have used games with seventh- and eighth-grade students and have been pleased with the results. The successful use of the games and the enthusiasm of the students have enco uraged me to make up mathematics card games of my own. “Black Jack,” which is one of mine, provides practice with positive and negative numbers. It is based on the actual card game and is easy to learn.

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