Paleoindians in beringia: evidence from arctic alaska

Excavations at the Mesa site in arctic Alaska provide evidence for a Paleoindian occupation of Beringia, the region adjacent to the Bering Strait. Eleven carbon-14 dates on hearths associated with Paleoindian projectile points place humans at the site between 9,730 and 11,660 radiocarbon years before present (years B.P.). The presence of Paleoindians in Beringia at these times challenges the notion that Paleoindian cultures arose exclusively in mid-continental North America. The age span of Paleoindians at the Mesa site overlaps with dates from two other cultural complexes in interior Alaska. A hiatus in the record of human occupation occurs between 10,300 and 11,000 years B.P. Late Glacial climatic fluctuations may have made northern Alaska temporarily unfavorable for humans and spurred their southward dispersal.     

Pre-Clovis mastodon hunting 13,800 years ago at the Manis site, Washington

The tip of a projectile point made of mastodon bone is embedded in a rib of a single disarticulated mastodon at the Manis site in the state of Washington. Radiocarbon dating and DNA analysis show that the rib is associated with the other remains and dates to 13,800 years ago. Thus, osseous projectile points, common to the Beringian Upper Paleolithic and Clovis, were made and used during pre-Clovis times in North America. The Manis site, combined with evidence of mammoth hunting at sites in Wisconsin, provides evidence that people were hunting proboscideans at least two millennia before Clovis.     

Nitrous oxide production in nearshore marine sediments

Coastal marine sediments are shown to be a net source of nitrous oxide. The rates of nitrous oxide flux from sediments in Narragansett Bay, Rhode Island, ranged from 20 to more than 900 nanomoles per square meter per hour. Sediments from a eutrophic area had higher rates of net nitrous oxide production than sediments from relatively unpolluted sites. The benthic, nitrous oxide source exceeds the nitrous oxide source to the bay from sewage treatment plant effluent.     

Mammoth-bone shaft wrench from murray springs, Arizona

Archeological excavations at Murray Springs, Cochise County, Arizona, in July 1967 uncovered a unique bone tool in the Clovis occupation level and in association with bones of a mammoth. The tool may be a wrench for straightening shafts of spears; if so, shaft diameters ranging from 14 to 17 millimeters were most likely used in hafting Clovis projectile points.     

日本海洋立法新发展及其对我国的影响

日本自进入21世纪以来,加强了国内的海洋立法,尤其是在海洋政策、海洋安全、海洋国土以及海洋资源方面的立法,以实施新的海洋战略。新的海洋立法为其在解决中日间有关钓鱼岛之争和东海划界产生有利影响的同时,对发展我国海洋战略空间、维护海上通道安全以及和平解决海洋争端产生了十分不利的影响。日本的海洋立法给予了我们一定的启示:(1)应加快制定新世纪国家海洋战略,以适应国际新形势;(2)完善综合应对海洋问题体制,以指导国内海洋事务;(3)进一步加强人才培养与海洋科技投入,实现我国海洋经济的可持续发展;(4)加强海上执法力量建设,有效地维护我国海洋权益;(5)增强民众海洋教育,提升全民海洋意识。研究亮点:对近年来日本海洋立法的新发展作了较为详细的介绍和分析,并分析了其可能对中国产生的影响。在此基础上,论述了日本海洋立法对中国的启示和意义。对完善国内海洋立法,综合性地处理海洋问题具有一定的参考价值。     

Isolation of 2,6-dibromophenol from the marine hemichordate, Balanoglossus biminiensis

2,6-Dibromophenol has been isolated from a luminous marine enteropneust, Balanoglossus biminiensis, found on intertidal beach areas at Sapelo Island, Georgia. This compound, responsible for the characteristic "iodoform-like" odor of these animals, is present in relatively large amounts; the estimated quantity per organism is 10 to 15 milligrams. Identity of the isolated substance as 2,6 dibromophenol is based on analyses of ultraviolet, infrared, and nuclear magnetic resonance spectra, mass spectrometry analysis, and on melting-point data.     

Comment on "Determining chondritic impactor size from the marine osmium isotope record"

Paquay et al. (Reports, 11 April 2008, p. 214) reported that osmium isotope ratios in marine sediments can be used to determine the size of a chondritic impactor. Their assumptions on the fate of an impacting projectile may need to be reassessed, however, because only a small, unpredictable fraction of the impactor ends up dissolved in seawater.     

3种金枪鱼的生物学研究进展

以大眼金枪鱼Thunnus obesus,黄鳍金枪鱼Thunnus albacares及蓝鳍金枪鱼Thunnus maccoyii为例,围绕金枪鱼生物学中的鱼龄与生长、摄食及繁殖3个方面,综述了现阶段金枪鱼生物学研究的常用方法与主要的研究成果,即金枪鱼为提高种群的合适度,形成的多个独特的生物学特征,如多生长增速拐点、机会捕食者及多种繁殖策略等。同时,针对金枪鱼生物学研究领域现存的不足,从研究方法、设备和技术手段等方面提出未来研究建议。     

Thermoluminescent determination of prehistoric heat treatment of chert artifacts

In recent years archeologists have become interested in the extent to which prehistoric peoples heat-treated chert prior to shaping it into tools. Thermoluminescent determination of the radiation dose accumulated by an artifact since it was formed or last heated provides a simple, reliable test for such heat treatment. This test can be applied to single artifacts without the need for raw source material for comparison. Results on 25 artifacts from four sites indicate that, for many chert sources, color and luster are not useful indicators of heat treatment by prehistoric peoples.     

Determining chondritic impactor size from the marine osmium isotope record

Decreases in the seawater 187Os/188Os ratio caused by the impact of a chondritic meteorite are indicative of projectile size, if the soluble fraction of osmium carried by the impacting body is known. Resulting diameter estimates of the Late Eocene and Cretaceous/Paleogene projectiles are within 50% of independent estimates derived from iridium data, assuming total vaporization and dissolution of osmium in seawater. The variations of 187Os/188Os and Os/Ir across the Late Eocene impact-event horizon support the main assumptions required to estimate the projectile diameter. Chondritic impacts as small as 2 kilometers in diameter should produce observable excursions in the marine osmium isotope record, suggesting that previously unrecognized impact events can be identified by this method.     

粤柘林东湾-南澳岛海洋牧场的海水营养状况及其等级评价

柘林湾-南澳岛海洋牧场由网箱养殖区、贝类底播区、海藻养殖区和人工鱼礁区等4个不同的功能区构成.为了了解海洋牧场建设过程中海水的营养状况及其变化趋势,根据海洋牧场2011-2012年春、夏、秋、冬4个航次海水营养盐的监测数据,分析不同功能区海水营养盐的时空分布特征,并采用N/P和潜在性富营养化评价模式对不同功能区的海水营养状况及其营养等级进行了评价.结果表明:(1)海洋牧场海域的无机氮(DIN)和活性磷酸盐(PO4-P)全年呈现自西北部柘林湾向东南海域递减、近岸向离岸递减的变化趋势.(2)NO3-N是DIN的主要存在形式,NO3-N/DIN的最大值出现在柘林湾内的网箱养殖区,且网箱养殖区DIN和PO4-p的年均值均远高于其他功能区,分别为0.726 mg/L和0.036 mg/L.(3)根据营养等级评价的结果,网箱养殖区和贝类底底播区全年平均处于磷中等限制的潜在性富营养状态,海藻养殖区全年平均处于磷限制的中度营养状态,人工鱼礁区全年平均处于良好的中度营养状态.因此,可以推断海洋牧场的建设对海洋环境具有一定的调节能力.     

Bone foreshafts from a clovis burial in southwestern montana

Formal and functional analyses of bone artifacts from a Clovis burial in southwestern Montana suggest that they were constructed to serve as (detachable or nondetachable) foreshafts for attaching fluted projectile points to lance shafts.     

木材泡沫铝层叠结构材在瞬态加载时的动力学特性

以木材、泡沫铝板为材料,经层叠制作2种型号(T5T10T5和T10T15T10)木材泡沫铝层叠结构靶板;利用一级轻气炮发射卵形头和平头杆弹对靶板进行瞬态加载试验;利用高速摄像机获取杆弹初始速度和侵彻图像,得到2种杆弹初始速度-剩余速度关系曲线及弹道极限速度,分析靶板抗侵彻性能和失效模式。结果表明:随着杆弹初始速度的逐渐增高,靶板对2种杆弹的抗侵彻性不同;卵形头杆弹的极限速度均高于平头杆弹,说明靶板对卵形头杆弹的抗侵彻性强于平头杆弹;随着初始速度增大,相同初始速度时卵形头杆弹的剩余速度大于平头杆弹,此时靶板对平头杆弹的抗侵彻性强于卵形头杆弹。2种杆弹贯穿靶板后,靶板变形和损伤模式相似,均为正面穿孔、背面脱落、孔口直径与杆弹直径接近;靶板背面中心处形成一定挠度,孔口边缘处挠度最大;当杆弹初始速度超过弹道极限速度,初始速度越大,整体变形越小,靶板越接近局部破坏。同时,两者存在区别,卵形头杆弹贯穿靶板,是因为瞬态加载使靶板失效变形;而平头杆弹贯穿靶板,是由于剪切使靶板损伤变形。     

环境保护的伦理思考

环境问题是全球性问题, 特别是发展中国家的重大问题, 关系到社会经济的可持续性发展。本文针对我国环境问题和民众环境伦理意识淡薄的实际, 提出环境保护中要提高人们伦理意识, 端正环保主体的道德态度和行为规范, 自觉选择环境治理技术, 实现无公害化生产;确保环境保护基本国策的落实, 实现社会经济可持续性发展战略的实施。探讨环境保护和建设中, 通过汲取传统文化中环境伦理精华, 提升环保从业人员环境伦理意识, 加大环保政策和法规执行力度, 强化环保宣传与教育等途径。指出提高公众环境伦理意识, 无须增加多少投资, 也能解决许多环境问题。参6     

Baffin island refugia older than 54,000 years

Two radiocarbon determinations on marine shells from the east coast of Baffin Island give ages exceeding 50,000 years. These findings indicate the existence of unglaciated areas ( refugia) between fiords occupied by outlet glaciers flowing toward Baffin Bay, from the central part of the Wisconsin ice sheet, over the Foxe Basin-Hudson Bay area.     

Recruitment dynamics in complex life cycles

Organisms living in the marine rocky intertidal zone compete for space. This, together with predation, physical disruption, and differing species tolerances to physiological stress, explains the structure of the ecological communities at some sites. At other sites the supply of larvae is limiting, and events in the offshore waters, such as wind-driven upwelling, explain the composition of intertidal communities. Whether the community ecology at a site is governed by adult-adult interactions within the site, or by limitations to the supply of larvae reaching the site, is determined by the regional pattern of circulation in the coastal waters. Models combining larval circulation with adult interactions can potentially forecast population fluctuations. These findings illustrate how processes in different ecological habitats are coupled.     

Isolation of Virus Capable of Lysing the Brown Tide Microalga, Aureococcus anophagefferens

Viruses have been hypothesized to control blooms of Aureococcus anophagefferens gen. et sp. nov. (Chrysophyceae), a marine phytoplankton that since 1985 has caused devastating summer blooms called "brown tide." By means of ultrafiltration methods, viruses specific to this alga were isolated from both the Great South Bay and Peconic Bay systems of Long Island, New York, during the summer bloom period of 1992. Cell lysis of healthy algal cultures was demonstrated, as well as continuing reinfection with serial transfers of cultures. Electron microscope surveys yielded images of phage-like virus particles with tails that could attach to A. anophagefferens cells within minutes of exposure. The isolation and cultivation of this virus highlights the need for further study of viral infection of eukaryotic algae and the potential for a better understanding of algal bloom control by viral infection.     

Redemptive communities: Indigenous knowledge,colonist farming systems,and conservation of tropical forests

This essay critically examines the emerging view among some ethnologists that replicable models of sustainable management of tropical forests may be found within the knowledge systems of contemporary indigenous peoples. As idealized epistemological types, several characteristics distinguishing “indigenous” from “modern” knowledge systems are described. Two culturally distinctive land use systems in Latin America are compared, one developed by an indigenous group, the Huastec Maya, and the other characteristic of colonist farms in Rondonia, Brazil. While each of these systems reflects a different cultural-historical tradition, I argue that the process of knowledge formation and cultural adaptation is coevolutionary and continuous in both cases. The very concept of “indigenous” as a discrete analytic category is questioned; indigenicity alone cannot explain local adaptation of farming systems. Rather than dichotomize indigenous and colonist knowledge as inherently different categories, differences in land use patterns between such social groups may be more accurately viewed as reflecting different points on a single epistemological continuum.     

基于GIS的长海海域环境信息分析

搜集长海海域海洋环境信息数据,结合水质综合评价、富营养化评价模型,采用GIS技术分析了长海海域环境质量。结果表明,长海海域pH、溶解氧空间分布比较均匀,大部分海域符合一类海水水质标准;石油类浓度均较低;化学需氧量、活性磷酸盐、无机氮空间分布相似,岛屿周边及岛屿之间浓度较高,而在海域开阔处浓度较低,分析主要受养殖活动和水体交换能力的影响;长海海域水体质量整体处于清洁水平,大部分海域未出现富营养化,只有在广鹿岛、大长山岛、乌蟒岛、海洋岛邻近海域出现轻度富营养化。     

The ecology of early man in southern Africa

It is not possible at present to demonstrate hominid occupation of southern Africa prior to the middle or late Pliocene, perhaps 3 million years ago. It may be the case that much, if not most, of the subcontinent was in fact uninhabited before that. The earliest hominid known to have lived in southern Africa is Australopithecus africanus. It was apparently replaced by Homo (?evolved into Homo) by 2 million years ago, at approximately the same time as A. robustus is first recorded locally. Homo and A. robustus then coexisted until perhaps 1 million years ago, after which Homo survived alone. There is no solid evidence that either of the southern African australopithecines made tools or accumulated bones. In fact, at the known sites, it now seems more likely that the bones, including those of the australopithecines themselves, were accumulated by carnivores. The known archeological record of southern Africa begins 2 million to 1.5 million years ago and the oldest stone tools may belong to the Oldowan Industry. Far better documentation exists for the succeeding Acheulean Industrial Complex, which was present in southern Africa almost certainly before 1 million years ago and persisted with modifications probably until sometime between 300,000 and 130,000 years ago. Although it is known that Acheulean peoples made handaxes, cleavers, and other stone tools, very little else is known about the activities of Acheuleans in southern Africa. Far more is known about their Middle and Later Stone Age successors. Southern African MSA peoples were perhaps among the earliest anywhere to take systematic advantage of aquatic resources for their subsistence, although they apparently did so far less effectively than did the LSA peoples who followed them. There are also contrasts between the ways in which MSA and LSA peoples dealt with terrestrial prey and between the contents of MSA and LSA artifact assemblages. The LSA peoples, for example, seem to have made much more extensive use of bone as a raw material, and they were the first to manufacture articles that are clearly interpretable as ornaments or art objects. From an evolutionary perspective, the LSA may represent a quantum advance over the MSA, perhaps correlated with the replacement of an archaic human physical type by the modem one. However, this must remain only a working hypothesis until much more is learned about the earliest LSA, dating to 35,000 to 40,000 years ago or more, and until there are adequate samples of well-provenienced MSA and early LSA physical remains. The later LSA, postdating 20,000 to 18,000 years ago, is reasonably well known. Later LSA peoples were probably at least partly responsible for the extinction of several large mammals in southern Africa about 10,000 years ago. By that date or shortly thereafter, at least some LSA peoples established basic hunting-gathering adaptations, which continued until the introduction and spread of agriculture and pastoralism, beginning roughly 2000 years ago. Thereafter, hunters and gatherers became progressively restricted in numbers and distribution, such that today only a very few exist, restricted to some of the most marginal environments of the subcontinent. It remains a major goal of southern African archeology to shed more light on the evolution and operation of hunting-gathering cultures during the vast time span when they covered all of southern Africa.