The Hohokam Canals at Pueblo Grande, Arizona

1960 ◽  
Vol 26 (2) ◽  
pp. 267-270 ◽  
Author(s):  
Richard B. Woodbury

AbstractA cross section of the surviving traces of two large prehistoric canals near Pueblo Grande, Phoenix, shows one to have originally been V-shaped in profile, about 6 m. wide and 4 m. deep, and the other U-shaped in profile, about 10 m. wide and 3 m. deep. Both were dug into coarse gravel and the broader (north) canal had been lined with brown clay subsequent to its construction and initial period of use. There is a possibility that the V-shaped South Canal was built first and perhaps abandoned when the North Canal was built. Both canals show evidence of repeated filling and clearing out, either by natural erosion due to a periodically swifter current or by the efforts of the Indians using the canals. Sherds under the banks and in the canals were too few for conclusive dating of construction and use, but suggest that this took place during the Soho phase of the Hohokam Classic period, that is, during the late 12th and the 13th centuries. Hohokam canals much older than this are known, and the occupation of nearby Pueblo Grande began earlier and lasted later than the Soho phase.

Author(s):  
Jeffery J. Clark ◽  
David Abbott

This chapter discusses the Hohokam Classic Period (ca. 1200–1450 ce) in southern Arizona. Two perspectives are presented for observed archaeological patterns. One perspective is from the Phoenix Basin center, a densely populated region on a trajectory of overexploitation and decline throughout much of the interval, despite the construction of massive irrigation works and architectural buildings that left impressive ruins. The other perspective is from the outlying valleys to the north and east of Phoenix that had much lower population densities. Here intense interaction between local majorities, and small, but socially resilient, Kayenta immigrants from northeast Arizona led to the development of an inclusive Salado ideology that transcended the identities of both groups. This ideology ultimately penetrated the Phoenix Basin when the latter was on the verge of collapse. This collapse was so complete that few pre-contact archaeological sites have been identified in the Hohokam region after 1450 ce.


1985 ◽  
Vol 22 (5) ◽  
pp. 768-773 ◽  
Author(s):  
Detlef Wolf

A reinterpretation of relative-uplift data associated with the deformed strandline of Pleistocene Lake Algonquin is presented. The new analysis is based on a dynamic model that allows for the finite rate of retreat of the Laurentide ice sheet and the viscous relaxation of the Earth's mantle. Attention is also paid to the effects of the shape of the load profile on the interpretation. In the context of this model the thickness of the lithosphere is constrained to be not more than 85 km. This value is based on the assumption of a model ice sheet with a parabolic cross section. If the load has a sharper edge, a thickness of 110 km is consistent with the data. These revised values slightly exceed Walcott's original estimate. They are, on the other hand, distinctly lower than the value of 200 km, which has recently been inferred by Peltier for the thickness of the North American lithosphere. The relations between the different estimates are briefly discussed. It is suggested that a reconciliation of the estimates may require that effects caused by geoidal perturbations be included in future analyses of strandline tilt.


Author(s):  
T. M. Murad ◽  
H. A. I. Newman ◽  
K. F. Kern

The origin of lipid containing cells in atheromatous lesion has been disputed. Geer in his study on atheromatous lesions of rabbit aorta, suggested that the early lesion is composed mainly of lipid-laden macrophages and the later lesion has a mixed population of macrophages and smooth muscle cells. Parker on the other hand, was able to show evidence that the rabbit lesion is primarily composed of lipid-laden cells of smooth muscle origin. The above studies and many others were done on an intact lesion without any attempt of cellular isolation previous to their ultrastructural studies. Cell isolation procedures have been established for atherosclerotic lesions through collagenase and elastase digestion Therefore this procedure can be utilized to identify the cells involved in rabbit atheroma.


Author(s):  
V. Mizuhira ◽  
Y. Futaesaku

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.


Author(s):  
J. P. Colson ◽  
D. H. Reneker

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.


2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.


2018 ◽  
Vol 69 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Daniela Gitea ◽  
Simona Vicas ◽  
Manuel Alexandru Gitea ◽  
Sebastian Nemeth ◽  
Delia Mirela Tit ◽  
...  

Our study compares the content in polyphenolic compounds and hypericin, in four species of Hypericum - H. perforatum L., H. maculatum Cr., H. hirsutum L., H. tetrapterum Fr. (syn. Hypericumacutum Mnch.) harvested from spontaneous flora in the north-western area of Transylvania, Romania. These species represent an important source of such compounds with different biological actions. After making the extracts, they were subjected to HPLC-SM analysis. The presence of rutoside in the largest amount (462.82 mg %) in the H. perforatum extract was observed, this containing most of the flavonoid heterosides. For the species H. maculatum, the presence in a much higher amount of the hyperoside (976.36 mg %) is characteristic compared to the other species. Quercetol is the best represented of the flavonoid aglycons, its concentration being the highest in H. hirsutum (659.66 mg %). The hypericin content ranges from 0.2171 g % in the H. tetrapterum extract, to 0.0314 g % in the methanol extract of H. maculatum.The highest antioxidant properties measured by FRAP method were recorded in the case of H. perforatum and H. maculatum.


2021 ◽  
Vol 32 (1) ◽  
pp. 41-55
Author(s):  
Robert H. Cobean ◽  
Dan M. Healan ◽  
María Elena Suárez

AbstractRecent excavations at Tula Chico, the monumental center for Tula's earliest settlement, revealed a long and complex history of occupation, beginning with its initial settlement in the Middle Classic period by Coyotlatelco peoples, when much of the region was under Teotihuacan's direct control. During the Epiclassic period, a program of monumental construction began that developed the monumental complex seen today over a period of about 200 years. Although Tula Chico was superseded by Tula Grande, the monumental center for the Early Postclassic city, it continued to be occupied and maintained until its destruction by fire. Tula Chico and Tula Grande show evidence of clear cultural continuity in ceramics, architecture, and sculpture, including “Toltec style” sculpture characteristic of Tula Grande that is present in temporally early contexts at Tula Chico.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 307
Author(s):  
Makoto Inoue ◽  
Atsushi Ugajin ◽  
Osamu Kiguchi ◽  
Yousuke Yamashita ◽  
Masashi Komine ◽  
...  

In this study, we investigated the effects of the Tibetan High near the tropopause and the North Pacific High in the troposphere on occurrences of hot or cool summers in Japan. We first classified Japan into six regions and identified hot and cool summer years in these regions from a 38-year sample (1980–2017) based on the monthly air temperature. To investigate the features of circulation fields over Asia during hot and cool summers in Japan, we calculated the composite differences (hot summer years minus cool summer years) of several variables such as geopotential height, which indicated significant high-pressure anomalies in the troposphere and lower stratosphere. These results suggest that both the North Pacific and the Tibetan Highs tend to extend to Japan during hot summer years, while cool summers seem to be associated with the weakening of these highs. We found that extension of the Tibetan High to the Japanese mainland can lead to hot summers in Northern, Eastern, and Western Japan. On the other hand, hot summers in the Southwestern Islands may be due to extension of the Tibetan High to the south. Similarly, the latitudinal direction of extension of the North Pacific High is profoundly connected with the summer climate in respective regions.


2021 ◽  
pp. 1-17
Author(s):  
Laurie D. Grigg ◽  
Kevin J. Engle ◽  
Alison J. Smith ◽  
Bryan N. Shuman ◽  
Maximilian B. Mandl

Abstract A multiproxy record from Twin Ponds, VT, is used to reconstruct climatic variability during the late Pleistocene to early Holocene transition. Pollen, ostracodes, δ18O, and lithologic records from 13.5 to 9.0 cal ka BP are presented. Pollen- and ostracode-inferred climatic reconstructions are based on individual species’ environmental preferences and the modern analog technique. Principal components analysis of all proxies highlights the overall warming trend and centennial-scale climatic variability. During the Younger Dryas cooling event (YD), multiple proxies show evidence for cold winter conditions and increasing seasonality after 12.5 cal ka BP. The early Holocene shows an initial phase of rapid warming with a brief cold interval at 11.5 cal ka BP, followed by a more gradual warming; a cool, wet period from 11.2 to 10.8 cal ka BP; and cool, dry conditions from 10.8 to 10.2 cal ka BP. The record ends with steady warming and increasing moisture. Post-YD climatic variability has been observed at other sites in the northeastern United States and points to continued instability in the North Atlantic during the final phases of deglaciation.


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