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1.
Sci Adv ; 5(4): eaaw0038, 2019 04.
Article in English | MEDLINE | ID: mdl-31001590

ABSTRACT

The process of sheep and goat (caprine) domestication began by 9000 to 8000 BCE in Southwest Asia. The early Neolithic site at Asikli Höyük in central Turkey preserves early archaeological evidence of this transformation, such as culling by age and sex and use of enclosures inside the settlement. People's strategies for managing caprines evolved at this site over a period of 1000 years, but changes in the scale of the practices are difficult to measure. Dung and midden layers at Asikli Höyük are highly enriched in soluble sodium, chlorine, nitrate, and nitrate-nitrogen isotope values, a pattern we attribute largely to urination by humans and animals onto the site. Here, we present an innovative mass balance approach to interpreting these unusual geochemical patterns that allows us to quantify the increase in caprine management over a ~1000-year period, an approach that should be applicable to other arid land tells.


Subject(s)
Animal Husbandry/statistics & numerical data , Animal Husbandry/standards , Nitrogen Isotopes/analysis , Salts/urine , Animal Husbandry/methods , Animals , Archaeology , Goats , Humans , Sheep , Turkey
2.
Nature ; 513(7519): 501-6, 2014 Sep 25.
Article in English | MEDLINE | ID: mdl-25219854

ABSTRACT

The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34 Myr ago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.


Subject(s)
Climate , Greenhouse Effect/history , Rain , Altitude , Animal Shells/chemistry , Animals , China , Desert Climate , Dust/analysis , Fossils , Gastropoda/chemistry , History, Ancient , Myanmar , Oxygen Isotopes , Seasons , Temperature , Tibet , Tooth/chemistry
4.
Proc Natl Acad Sci U S A ; 98(21): 11891-6, 2001 Oct 09.
Article in English | MEDLINE | ID: mdl-11572943

ABSTRACT

Between A.D. 900 and 1150, more than 200,000 conifer trees were used to build the prehistoric great houses of Chaco Canyon, New Mexico, in what is now a treeless landscape. More than one-fifth of these timbers were spruce (Picea) or fir (Abies) that were hand-carried from isolated mountaintops 75-100 km away. Because strontium from local dust, water, and underlying bedrock is incorporated by trees, specific logging sites can be identified by comparing (87)Sr/(86)Sr ratios in construction beams from different ruins and building periods to ratios in living trees from the surrounding mountains. (87)Sr/(86)Sr ratios show that the beams came from both the Chuska and San Mateo (Mount Taylor) mountains, but not from the San Pedro Mountains, which are equally close. Incorporation of logs from two sources in the same room, great house, and year suggest stockpiling and intercommunity collaboration at Chaco Canyon. The use of trees from both the Chuska and San Mateo mountains, but not from the San Pedro Mountains, as early as A.D. 974 suggests that selection of timber sources was driven more by regional socioeconomic ties than by a simple model of resource depletion with distance and time.

5.
Science ; 289(5484): 1542-1546, 2000 Sep 01.
Article in English | MEDLINE | ID: mdl-10968788

ABSTRACT

Fossil rodent middens and wetland deposits from the central Atacama Desert (22 degrees to 24 degrees S) indicate increasing summer precipitation, grass cover, and groundwater levels from 16.2 to 10.5 calendar kiloyears before present (ky B.P.). Higher elevation shrubs and summer-flowering grasses expanded downslope across what is now the edge of Absolute Desert, a broad expanse now largely devoid of rainfall and vegetation. Paradoxically, this pluvial period coincided with the summer insolation minimum and reduced adiabatic heating over the central Andes. Summer precipitation over the central Andes and central Atacama may depend on remote teleconnections between seasonal insolation forcing in both hemispheres, the Asian monsoon, and Pacific sea surface temperature gradients. A less pronounced episode of higher groundwater levels in the central Atacama from 8 to 3 ky B.P. conflicts with an extreme lowstand of Lake Titicaca, indicating either different climatic forcing or different response times and sensitivities to climatic change.

6.
Science ; 288(5465): 497-9, 2000 Apr 21.
Article in English | MEDLINE | ID: mdl-10775105

ABSTRACT

Metasedimentary rocks of the Greater Himalaya are traditionally viewed as Indian shield basement that has been thrust southward onto Lesser Himalayan sedimentary rocks during the Cenozoic collision of India and Eurasia. Ages determined from radioactive decay of uranium to lead in zircon grains from Nepal suggest that Greater Himalayan protoliths were shed from the northern end of the East African orogen during the late Proterozoic pan-African orogenic event. These rocks were accreted onto northern Gondwana and intruded by crustal melts during Cambrian-Ordovician time. Our data suggest that the Main Central thrust may have a large amount of pre-Tertiary displacement, that structural restorations placing Greater Himalayan rocks below Lesser Himalayan rocks at the onset of Cenozoic orogenesis are flawed, and that some metamorphism of Greater Himalayan rocks may have occurred during early Paleozoic time.

7.
Am J Public Health ; 87(10): 1709-11, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9357361

ABSTRACT

OBJECTIVES: This study assessed the effect of unintended pregnancy on breast-feeding behavior. METHODS: All women delivering a live birth between January 1, 1995, and July 31, 1996 (n = 33,735), in the 15-county central New York region were asked whether they had intended to become pregnant and their breast-feeding plans. RESULTS: Women with mistimed pregnancies, and pregnancies that were not wanted were significantly less likely to breast-feed than were women whose pregnancies were planned. After adjustment for confounding variables and contraindications for breast-feeding, the odds ratios of not breast-feeding remained significant. CONCLUSIONS: Promoting breast-feeding among women with unintended pregnancies is important to improve health status.


Subject(s)
Breast Feeding/psychology , Pregnancy, Unwanted/psychology , Pregnancy/psychology , Female , Humans , New York
8.
Phys Rev A ; 54(4): 2698-2702, 1996 Oct.
Article in English | MEDLINE | ID: mdl-9913779
9.
Science ; 250(4987): 1549-52, 1990 Dec 14.
Article in English | MEDLINE | ID: mdl-17818282

ABSTRACT

Layered carbonate and silica encrust fault fractures exposed in Trench 14 near Yucca Mountain, site of the proposed high-level nuclear waste repository in southern Nevada. Comparison of the stable carbon and oxygen isotopic compositions of the fracture carbonates with those of modern soil carbonates in the area shows that the fracture carbonates are pedogenic in origin and that they likely formed in the presence of vegetation and rainfall typical of a glacial climate. Their isotopic composition differs markedly from that of carbonate associated with nearby springs. The regional water table therefore remained below the level of Trench 14 during the time that the carbonates and silica precipitated, a period probably covering parts of at least the last 300,000 years.

10.
J Parasitol ; 76(2): 153-61, 1990 Apr.
Article in English | MEDLINE | ID: mdl-2108234

ABSTRACT

Intracellular growth of protozoan parasite Babesia bovis has been followed to study the effect of some chemical agents on growth regulation. Using an in vitro parasite culture system we present evidence that the normal growth of the parasite is dependent upon available calcium and a Ca2(+)-binding protein, calmodulin, because sequestration of either of these 2 components from the culture medium causes inhibition of parasitic growth. Further studies demonstrate that the parasite contains a protein kinase that can phosphorylate a 40-kDa parasitic protein and its activity is regulated by calcium and calmodulin. Both the enzyme and its substrate are present in the membrane of the parasite. In addition, the parasite also contains a highly active protein kinase C activity that is documented by phosphorylating histone, a known substrate for protein kinase C. These findings suggest a possible correlation between the growth of parasite and calcium/calmodulin-dependent protein phosphorylation activity.


Subject(s)
Babesia/metabolism , Calcium/pharmacology , Calmodulin/pharmacology , Protozoan Proteins/metabolism , Animals , Babesia/enzymology , Babesia/growth & development , Calmodulin/antagonists & inhibitors , Culture Media , Imidazoles/pharmacology , Phosphorylation , Protein Kinases/metabolism , Threonine/metabolism
11.
Steroids ; 31(2): 175-87, 1978 Feb.
Article in English | MEDLINE | ID: mdl-663962

ABSTRACT

A specific and sensitive gas chromatographic method was used to investigate the concentration of pregnanediol glucuronide in urine in relation to the time of ovulation. Serum LH and progesterone concentrations in the same subjects were used as evidence for the occurrence of ovulation. The urinary concentration of pregnanediol glucuronide in 24-hour collections and in overnight specimens increased 2-fold or more from the day of the midcycle LH peak to the time of predicted ovulation (24-48 hour after the LH peak) in parallel with the rise in serum progesterone concentration.


Subject(s)
Luteinizing Hormone/blood , Ovulation , Pregnanediol/urine , Progesterone/blood , Chromatography, Gas , Female , Humans
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