Rapid fluctuations in sea level recorded at huon peninsula during the penultimate deglaciation

About 140,000 years ago, the breakup of large continental ice sheets initiated the Last Interglacial period. Sea level rose and peaked around 135,000 years ago about 14 meters below present levels. A record of Last Interglacial sea levels between 116,000 years to 136, 000 years ago is preserved at reef VII of the uplifted coral terraces of Huon Peninsula in Papua New Guinea. However, corals from a cave situated about 90 meters below the crest of reef VII are 130, 000 +/- 2000 years old and appear to have grown in conditions that were 6 degreesC cooler than those at present. These observations imply a drop in sea level of 60 to 80 meters. After 130,000 years, sea level began rising again in response to the major insolation maximum at 126,000 to 128,000 years ago. The early (about 140,000 years ago) start of the penultimate deglaciation, well before the peak in insolation, is consistent with the Devils Hole chronology.     

Human adaptation and plant use in highland New Guinea 49,000 to 44,000 years ago

After their emergence by 200,000 years before the present in Africa, modern humans colonized the globe, reaching Australia and New Guinea by 40,000 to 50,000 years ago. Understanding how humans lived and adapted to the range of environments in these areas has been difficult because well-preserved settlements are scarce. Data from the New Guinea Highlands (at an elevation of ~2000 meters) demonstrate the exploitation of the endemic nut Pandanus and yams in archaeological sites dated to 49,000 to 36,000 years ago, which are among the oldest human sites in this region. The sites also contain stone tools thought to be used to remove trees, which suggests that the early inhabitants cleared forest patches to promote the growth of useful plants.     

Mid-recent human occupation and resource exploitation in the bismarck archipelago

Human settlement of the Bismarck Archipelago occurred by 6000 to 7500 years ago. Early inhabitants of New Ireland drew on widely dispersed stone sources, including obsidian from Talasea (New Britain), whereas those after about 3000 years ago used either stone from more local sources or obsidian from Lou Island (Admiralty Islands group) or Talasea. The dates and resource changes support a gradualist model of Melanesian settlement.     

Symmetrical erosive peripheral polyarthritis in the Late Archaic Period of Alabama

Rheumatoid arthritis was first described unambiguously in 1800, but its etiology and historical origins are still obscure. Definite rheumatoid arthritis has not been demonstrated in pre-19th century Old World skeletal remains. Six individuals who lived 3000 to 5000 years ago in northwestern Alabama and present erosive polyarthritis characteristic of rheumatoid arthritis are described. The diagnosis raises the possibility that rheumatoid arthritis can be associated with a New World pathogen or allergen.     

Uplifted marine terraces along the alpine fault, new zealand

Three types of evidence indicate that marine terraces are widespread in the Southern Alps of New Zealand. (i) Remnants of shore platforms occur as distinct levels of notched ridge crests and flat summits; degraded sea cliffs are common. (ii) Scattered quartz beach pebbles occur on 16 of 18 levels of exhumed shore platforms in the Fox- Franz Josef type area to altitudes as high as 1700 meters. (iii) Altitudinal spacings of New Zealand terrace flights allow correlation with 18 dated global marine terraces at New Guinea, which were formed during glacio-eustatic highstands of sea level within the last 336 x 10(3) years. Inferred uplift rates at Fox-Franz Josef increased from 3.2 to 7.8 meters per 10(3) years since about 135 x 10(3) to 140 x 10(3) years ago, presumably because of increased convergence between the Pacific and Australian plates.     

Coral record of equatorial sea-surface temperatures during the penultimate deglaciation at huon peninsula

Uplifted coral terraces at Huon Peninsula, Papua New Guinea, preserve a record of sea level, sea-surface temperature, and salinity from the penultimate deglaciation. Remnants have been found of a shallow-water reef that formed during a pause, similar to the Younger Dryas, in the penultimate deglaciation at 130,000 +/- 2000 years ago, when sea level was 60 to 80 meters lower than it is today. Porites coral, which grew during this period, has oxygen isotopic values and strontium/calcium ratios that indicate that sea-surface temperatures were much cooler (22 degrees +/- 2 degreesC) than either Last Interglacial or present-day tropical temperatures (29 degrees +/- 1 degreesC). These observations provide further evidence for a major cooling of the equatorial western Pacific followed by an extremely rapid rise in sea level during the latter stages of Termination II.     

Holocene sea level changes at the coast of dor, southeast mediterranean

Geological, geomorphological, and archeological data of changes in sea level during the Holocene at the Mediterranean coast of Dor provide a eustatic curve of the region. This curve shows that sea level was approximately 2 meters below the present level 4000 years ago, rose to 1 meter below the present level 3000 years ago, and was 1 meter higher than the present level 1500 years ago. It then dropped to 1 meter below the present level about 800 years ago.     

Earthquake-caused landslides: a major disturbance to tropical forests

Earthquakes occasionally denude large areas of tropical forest: for example, 54 square kilometers in Panama in 1976 and 130 square kilometers in New Guinea in 1935. Earthquake rates in New Guinea, but not in Panama, are sufficiently high so that substantial areas of disturbed, nonclimax forest may accumulate. In New Guinea, earthquake-caused landslides are as important as tree falls in the disturbance regime.     

Lactate dehydrogenase electrophoretic variant in a New Guinea Highland population

Six examples of a variation in the LDH-A subunit have been detected in 408 samples from three exogamous clans in the New Guinea Highlands. The New Guinea variant is similar to the Memphis-4 variant. Origin of the New Guinea variant could not be traced by genealogy but it seems likely to have persisted for several generations.     

Astronomical theory of climatic change: support from new Guinea

Radiocarbon and thorium-230 dates of uplifted coral reef terraces on New Guinea appear to support theories of glaciation which utilize Milankovitch cycles as a controlling trigger mechanism. In addition to high sealevel stands recognized by other workers, the New Guinea data clearly indicate a marine transgression between 50,000 and 35,000 years before the present. A eustatic sea level curve reconstructed from field observations and radiometric dates shows a close correlation with temperature fluctuations in high latitudes as predicted by astronomical data.     

Carbon-14 time scale extended: comparison of chronologies

Thermal diffusion isotopic enrichment of carbon-14 has extended the radiocarbon dating range to about 75,000 years ago. Twenty-eight samples obtained up to June 1976, mainly from northwest Europe, were dated. Consideration of the basic assumptions of carbon-14 dating and of the sources of contamination indicates that the ages are generally reliable. Together with the pollen analytic and stratigraphic the dates yield a more detailed radiocarbon time scale for climatic variations in northwest Europe, showing three early glacial interstades. The radiocarbon time scale agrees with the Camp Century chronology and with the thorium-230 ages of corals representing high sea level stands on New Guinea. Ther is a discrepancy between the radiocarbon time scale and the deep-sea chronology, which may be due to correlation errors. With a modified interpretation of the correlation, all four time scales agree within the estimated experimental uncertainties of the dating techniques used.     

Discovery of microwave emission from four nearby solar-type g stars

Radio waves from the sun were detected 50 years ago, but the microwave detection of other single solar-type stars has remained a challenge. Here, the discovery of four solar-type radio stars is reported. These "solar twin" G stars are radio sources up to 3000 times stronger than the quiet sun. The microwaves most likely originate from a large number of relativistic electrons, possibly produced along with coronal heating, a process that is not understood. Two of the stars are younger than the sun and rotate more rapidly; the dynamo process in the stellar interior is therefore presumably more vigorous, resulting in enhanced coronal activity. One of the detections, however, is an old, metal-deficient G dwarf.     

Effects of water application uniformity using a center pivot on winter wheat yield,water and nitrogen use efficiency in the North China Plain

In recent years, the use of fertigation technology with center pivot irrigation systems has increased rapidly in the North China Plain(NCP). The combined effects of water and nitrogen application uniformity on the grain yield, water use efficiency(WUE) and nitrogen use efficiency(NUE) have become a research hotspot. In this study, a two-year field experiment was conducted during the winter wheat growing season in 2016–2018 to evaluate the water application uniformity of a center pivot with two low pressure sprinklers(the R3000 sprinklers were installed in the first span, the corresponding treatment was RS; the D3000 sprinklers were installed in the second span, the corresponding treatment was DS) and a P85 A impact sprinkler as the end gun(the corresponding treatment was EG), and to analyze its effects on grain yield, WUE and NUE. The results showed that the water application uniformity coefficients of R3000, D3000 and P85 A along the radial direction of the pivot(CU_H) were 87.5, 79.5 and 65%, respectively. While the uniformity coefficients along the traveling direction of the pivot(CU_C) were all higher than 85%. The effects of water application uniformity of the R3000 and D3000 sprinklers on grain yield were not significant(P0.05); however, the average grain yield of EG was significantly lower(P0.05) than those of RS and DS, by 9.4 and 11.1% during two growing seasons, respectively. The coefficients of variation(CV) of the grain yield had a negative correlation with the uniformity coefficient. The CV of WUE was more strongly affected by the water application uniformity, compared with the WUE value, among the three treatments. The NUE of RS was higher than those of DS and EG by about 6.1 and 4.8%, respectively, but there were no significant differences in NUE among the three treatments during the two growing seasons. Although the CU_H of the D3000 sprinklers was lower than that of the R3000, it had only limited effects on the grain yield, WUE and NUE. However, the cost of D3000 sprinklers is lower than that of R3000 sprinklers. Therefore, the D3000 sprinklers are recommended for winter wheat irrigation and fertigation in the NCP.     

Late Holocene climate and cultural changes in the southwestern United States

Columnar stalagmites in caves of the Guadalupe Mountains during the late Holocene record a 4000-year annually resolved climate history for the southwestern United States. Annual banding, hiatuses, and high-precision uranium-series dating show a present day-like climate from 4000 to 3000 years ago, following a drier middle Holocene. A distinctly wetter and cooler period from 3000 to 800 years ago was followed by a period of present day-like conditions, with the exception of a slightly wetter interval from 440 to 290 years before the present. The stalagmite record correlates well with the archaeological record of changes in cultural activities of indigenous people. Such climate change may help to explain evidence of dwelling abandonment and population redistribution.     

Molecular analysis by mass spectrometry

New ionization methods combined with powerful analyzers, detectors, and data systems have made mass spectrometry a versatile tool for molecular analysis. Samples consisting of nanogram quantities of hundreds of unique components are routinely analyzed. In favorable cases samples as small as 2.5 x 10(-14) gram and samples with masses of more than 3000 atomic mass units have been successfully examined.     

甘蔗的起源与进化

Ｓａｃｃｈａｒｕｍｏｆｆｉｃｉｎａｒｕｍ在世界上已形成几个多样性中心，如新几内亚、印尼东部和南太平洋群岛等。但多样性中心并不一定就是起源中心。Ｓ．ｏｆｆｉｃｉｎａｒｕｍ的起源中心是印尼东部－新几内亚地区。此外，还有其他一些地区被认为是起源中心，如中国、印度、东南亚，但证据还不够充分，有待于进一步证实。Ｓ．ｏｆｆｉｃｉｎａｒｕｍ是通过Ｓ．ｓｐｏｎｔａｎｅｕｍ与其他属的植物（包括Ｅｒｉａｎｔｈｕｓａｒｕｎｄｉｎａｃｅｕｓ、Ｍｉｓｃａｎｔｈｕｓｓｐ．等）的种质渗透而进化来的，进化的中间阶段是Ｓ．ｒｏｂｕｓｔｕｍ。种质渗透的第一步可能是在印尼东部，然后一些材料被传到新几内亚，通过漫长的自然和人工选择而进化成Ｓ．ｏｆｆｉｃｉｎａｒｕｍ。Ｓ．ｓｉｎｅｎｓｅ和Ｓ．ｂａｒｂｅｒｉ可能是Ｓ．ｏｆｆｉｃｉｎａｒｕｍ传到中国和印度后，分别与Ｓ．ｓｐｏｎｔａｎｅｕｍ及近缘植物发生种质渗透而形成的。但也有一些学者认为，一些Ｓ．ｂａｒｂｅｒｉ无性系独立于Ｓ．ｏｆｆｉｃｉｎａｒｕｍ。     

Human origins

New discoveries combine to indicate that all the major steps in human evolution took place in Africa. Skeletal analysis of oldest human forbears around 3 million years ago reveal many anatomical similarities to African Great Apes. These and biochemical resemblances indicate a common ancestry for humans and apes, perhaps only a few million years earlier. Enlarged knowledge through recent recovery of skeletons of several successive stages in the line leading to modern peoples shows that many attributes or skills by which we define humanity arose much more recently in time than heretofore believed.     

Asynchronous bends in Pacific seamount trails: a case for extensional volcanism?

The Gilbert Ridge and Tokelau Seamounts are the only seamount trails in the Pacific Ocean with a sharp 60 degrees bend, similar to the Hawaii-Emperor bend (HEB). These two bends should be coeval with the 47-million-year-old HEB if they were formed by stationary hot spots, and assuming Pacific plate motion only. New 40Ar/39Ar ages indicate that the bends in the Gilbert Ridge and Tokelau seamount trail were formed much earlier than the HEB at 67 and 57 million years ago, respectively. Such asynchronous bends cannot be reconciled with the stationary hot spot paradigm, possibly suggesting hot spot motion or magmatism caused by short-term local lithospheric extension.     

Postglacial change in sea level in the Western north atlantic ocean

Radioactive carbon determinations of the age of peat indicate that at Bermuda, southern Florida, North Carolina, and Louisiana the relative sea level has risen at approximately the same rate, 2.5 x 10(-3) foot per year (0.76 x 10(-3) meter per year), during the past 4000 years. It is proposed tentatively that this is the rate of eustatic change in sea level. The rise in sea level along the northeastern coast of the United States has been at a rate much greater than this, indicating local subsidence of the land. Between Cape Cod and northern Virginia, coastal subsidence of 13 feet appears to have occurred between 4000 and 2000 years ago and has continued at a rate of about 1 x 10(-3) foot per year since then. On the northeastern coast of Massachusetts, subsidence of 6 feet occurred between 4000 and 3000 years ago; since then sea level has risen at about the eustatic rate. Between 12,000 and 4000 years ago, sea level rose at an average of about 11 x 10(-3) foot per year. The part played by local subsidence or temporary departures from the average rate during this period is uncertain.     

Timing of millennial-scale climate change in Antarctica and Greenland during the last glacial period

A precise relative chronology for Greenland and West Antarctic paleotemperature is extended to 90,000 years ago, based on correlation of atmospheric methane records from the Greenland Ice Sheet Project 2 and Byrd ice cores. Over this period, the onset of seven major millennial-scale warmings in Antarctica preceded the onset of Greenland warmings by 1500 to 3000 years. In general, Antarctic temperatures increased gradually while Greenland temperatures were decreasing or constant, and the termination of Antarctic warming was apparently coincident with the onset of rapid warming in Greenland. This pattern provides further evidence for the operation of a "bipolar see-saw" in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales.