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1.
Cerumen in American Indians: genetic implications of sticky and dry types   总被引:2,自引:0,他引:2  
Occurrence of sticky and dry cerumen was determined in 483 Indians from various tribes of the United States. The elevated frequencies of the allele for dry cerumen, found in Indians of pure ancestry, support the theory of the mongoloid origin of the American Indian. Potential application of cerumen quality as a marker for genetic and anthropological studies is discussed.  相似文献   

2.
An electrophoretically slow hemoglobin variant, in which the structural change involves the replacement of a glutamyl residue by alanyl at position beta-22, was reported in two groups of North American Indians: hemoglobin-G Coushatta, in Alabama-Coushatta Indians in Texas; and hemoglobin-G Saskatoon, in descendants of Santee Indians living in Canada. Hemoglobin-G Hsin-Chu, found in Taiwan in a Chinese from the northern Chinese province of Liaoning, is now shown to have the same structural anomaly.  相似文献   

3.
The belief that the use of fish fertilizers originated among North American Indians, and was communicated as such by Squanto to the Plymouth settlers, has achieved the status of folklore and is therefore difficult to challenge. However, examination of the documentary evidence of Squanto's history and of native cultivation practices, and a cultural analysis of the implications of the use of fish fertilizer, have produced complementary lines of evidence. This evidence indicates that widely held beliefs about the "manner of the Indians" should be revised: Squanto's advice at Plymouth is probably best viewed as an interesting example of culture contact, one in which a native "culture-bearer" conveyed a technological idea from one group of Europeans to another.  相似文献   

4.
In an examination of the blood of 708 Eskimos, 200 Aleuts, and 44 Indians in Alaska for abnormal types of hemoglobin, only normal hemoglobin A was detected. It may be concluded that abnormal hemoglobins in these races are rare if they occur at all.  相似文献   

5.
Two populations of North Carolina have been analyzed for hemoglobin patterns by paper electrophoresis. Of 534 Cherokee Indians, both mixed and full bloods, all showed normal hemoglobin. Lumbee Indians of less certain ethnic status had 1.7 percent of hemoglobin S, an equal amount of hemoglobin C, and one possible hemoglobin D trait among 1332 bloods studied.  相似文献   

6.
Human visual ecology and orientation anisotropies in acuity   总被引:1,自引:0,他引:1  
The visual environment of Cree Indians from the east coast of James Bay, Quebec, is different from that of city-raised Euro-Canadians. So also are their corresponding orientation anisotropies in visual acuity. A Euro-Canadian sample exhibited the usual higher resolution for vertically and horizontally oriented gratings as compared with oblique orientations, while a Cree Indian sample did not. The most parsimonious explanation of these acuity differences is that orientation-specific detectors in humans are tuned by the early visual environment.  相似文献   

7.
The delta 15N values of bone collagen from Eskimos and from Northwest Coast Indians dependent on salmon fishing are about 10 per mil more positive than those from agriculturalists in historic times. Among prehistoric humans, two groups dependent on marine food sources show bone collagen delta 15N values that are 4 to 6 per mil more positive than those from two agricultural groups. The nitrogen isotope ratios of bone collagen from prehistoric inhabitants of the Bahamas are anomalously low for reasons that relate to the biogeochemical cycle of nitrogen in coral reefs.  相似文献   

8.
Albumin Naskapi: a new variant of serum albumin   总被引:3,自引:0,他引:3  
An apparently new Variant of human serum albumin, albumin Naskapi, has been found in high frequency in the Naskapi Indians of Quebec and, in lower frequency,in other North American Indians.The family and population data of the albumin are consistent with its inheritance as a simple autosomal trait Controlled by a gene designated Al Naskapi. This gene is allelic with the gene Al(A) which controls the common albumin.Both homozygotes and heterozygotes have been distinguished. This is the first report of a homozygote for an albumin Variant.  相似文献   

9.
Atypical cholinesterase gene E1a: rarity in Negroes and most Orientals   总被引:2,自引:0,他引:2  
Development of a rapid screening test for atypical cholinesterase in serum enabled large-scale surveys of populations. The frequency of the heterozygous trait among Greeks, Yugoslavs, and East Indians was similar to that among United States Caucasians (2.8 to 3.3 percent). In trait frequency, U.S. Negroes were intermediate (1.05 percent) between Congolese Africans (0.29 percent) and U.S. Whites (3.3 percent). The gene was absent from or very rare in populations originating in East Asia (Taiwanese, Japanese, Filipinos, and Eskimos). Prolonged apnea during anesthesia from administration of succinylcholine caused by homozygosity for this gene, is expected to be extremely rare among populations of Negroes and East Asians.  相似文献   

10.
为实现澳洲坚果的精准施肥,本研究以4、8、25 a的H2澳洲坚果树为试材,采用个体收获法,采集以树干为中心,树冠滴水线外约10 cm处(与其他树树冠交叉处)为边的整个圆内的不同距离、不同土层根系,并按其大小进行分级,清冼晾干后测其直径大小、鲜重和水分系数,分析根系在土层内的分布特点。结果表明:(1)4、8 a树0~20 cm土层根系干重显著高于其他层次,而25 a树20~40 cm土层根系分布最多,3种树龄0~40 cm土层根系干重占总根干重比例大于72%;(2)8、25 a树0~20 cm土层末级根干重占总末级根干重比例约为60%,而4 a树仅为44.8%;(3)4、8 a树离树干0~50 cm范围总根干重显著高于50 cm外总根干重,而25 a树50 cm外根干重显著高于0~50 cm范围内根干重,并且8、25 a树50 cm末级根干重占总末级根重比例高于90%,而4 a树则高于68%;(4)除了末级根,3种树龄根系干重基本上是随着根直径减少而减少。  相似文献   

11.
The low population densities and impermanent settlements of Amazonian Indians are often interpreted as adaptations to a fauna that offers limited protein resources and is rapidly depleted by hunting. Data spanning the 10-year life cycle of one northwestern Amazonian settlement show that variations in hunt yields result from temporal variations in peccary (Tayassu pecari and T. tajacu) kills that appear extrinsic to native population size. After 10 years, hunting success remained high and the kill rates for most prey did not suggest depletion. An array of environmental factors accounts for the incipient settlement relocation observed.  相似文献   

12.
种稻对周围旱地土壤盐分和土壤水分含量的影响   总被引:1,自引:0,他引:1  
为了研究种稻对周围旱地影响的程度和范围,选择稻旱田之间无沟和有沟相隔型两种类型,以不受种稻影响的老旱田作对照,在距稻田50、80、150和200m处各埋设定位观测井,监测种稻对地下水埋深、土壤水分含量和土壤盐分含量的影响。结果表明,耕层土壤水分含量与地下水埋深相关极显著,耕层土壤盐分含量与地下水埋深相关极显著,在上升期,旱田距稻田距离与地下水埋深相关极显著。因此,稻旱田之间无沟相隔时,种稻对周围旱地的影响表现为稻田水直接向旱田侧渗,而使距稻田附近旱田的地下水位上升,在距稻田220.7m内地下水位会上升到危害旱作物生长的程度;稻旱田之间有沟相隔时,种稻会导致稻旱田之间排水沟水位上升,从而对周围旱田产生不利影响,这种影响即可通过沟水向旱田的侧渗发生,又表现在阻止旱田的排水上,其不利影响范围在200m以内。  相似文献   

13.
从不同品种、不同施肥水平以及不同密度的角度,研究了高产水稻干物质积累的规律。结果表明:中早熟品种比中熟品种齐穗期以前干物质生产旺盛,齐穗期以后则较慢,中熟品种比中早熟品种从齐穗期至成熟期群体干物质增加量多,最终群体总干物质大,穗干重也大;穗干重,从齐穗期至成熟期群体干物质增加重,随着施肥量的增加和移植密度的减少而逐渐增多。  相似文献   

14.
旱稻干物质生产和分配的研究   总被引:7,自引:0,他引:7  
 为了探讨旱地条件下旱稻品种干物质生产和分配以及籽粒灌浆过程的特点,1986年和1987年在北京农业大学种植5个旱稻品种。用Hunt的生长分析法研究其干物质生产,结果表明旱稻品种的干物质生产和分配与水稻品种不相同。因不同生育阶段群体生长率、净同化率和光合势对旱稻品种总干重的影响不同。籽粒干物质积累过程用Logistic生长曲线拟合,符合度达极显著水平。  相似文献   

15.
自块茎膨大始期起,对不同生育期的马铃薯植株采样分部位进行测量研究。研究表明,干物质是构成马铃薯产量形成的物质基础,干物质的分配方向是决定块茎产量高低的重要因素。克新19号的块茎干物质分配一开始即呈直线增长,迅速达到一个较高水平。叶面积在4304.70~5114.35cm2时块茎干物质积累速度最快,保持在每天每株4.837~5.637g,并且持续时间长。  相似文献   

16.
Because Plains Indians, as well as some other groups of Native Americans, generally perceived people and animals as closely related, medical therapies and preventive regimes in human and veterinary medical practice often overlapped. The sense of partnership that mounted people shared with their horses dictated that it was appropriate for certain equine remedies to be similar to those used for themselves. Horses, as well as people, could possess useful knowledge in the realm of curing. Reciprocity between humankind and nature was expressed by the interactive healing powers of people and horses as well as by recorded examples of the connection that existed between human and equine health maintenance measures and medical procedures.  相似文献   

17.
从单茎水平上探讨了25个水稻两系杂种(含亚种间)抽穗结实期叶、茎鞘、穗以及单茎植株干物质积累、分配动态;考察了干物质积累、分配与籽粒产量的关系,并通过杂种与其相应父本的差异比较,分析了干物质积累的杂种优势,结果表明:杂种干物质变化存在因组合不同而异的特点,总体上开花期叶片和茎鞘部干物质积累达到最大值,穗部和单茎植株干物质积累在籽粒灌浆末期达到最大值.叶和茎鞘干物质所占比例从抽穗之日起呈下降趋势,穗部所占比例则一直上升;抽穗后第1~7d,茎鞘为干物质的主要贮存器官,至抽穗后第14d,穗部转变为干物质的主要贮存器官.单茎籽粒产量与抽穗后叶干物质积累呈正相关关系,且以抽穗后第1~7d相关系数较大;抽穗后第1d茎鞘干物质积累与单茎籽粒产量呈正相关关系,自第7d始转为负相关关系;籽粒产量与抽穗后穗部和单茎干物质积累量呈正相关关系;籽粒产量与单茎干物质积累在各器官中分配的相关趋势和籽粒产量与各器官干物质积累的相关趋势基本一致.多数组合抽穗后叶、茎鞘、单茎植株干物质积累表现出负向父本优势,单茎穗干物质则表现出正向父本优势的组合数多,单茎籽粒产量和结实率的父本优势表现出因组合不同而异的特点.  相似文献   

18.
温室番茄同步叶片修剪的TOMSIM模拟与验证   总被引:6,自引:0,他引:6  
摘 要:通过TOMSIM模拟与温室试验研究了同步叶片修剪对温室番茄品种 “Capita”干物质生产与分配的影响。结果表明, TOMSIM模拟试验与温室试验相当吻合。同步叶片修剪,一方面,显著降低LAI与生长率,从而导致单位面积植株总干重的显著降低;另一方面,显著减少营养生长库强,有利于干物质分配到生殖生长库器官,提高果实累积干物质分配率,从而补偿因单位面积植株总干重降低而引起的果实干重的降低。植株密度对果实累计干物质分配率没有显著影响,增加植株密度能增加LAI。同步叶片修剪加高密度能显著提高单位面积果实干重。  相似文献   

19.
迟中稻低棚深沟肥床旱育中大苗研究初报   总被引:3,自引:0,他引:3  
采用低棚深沟肥床旱育秧的技术,培育迟中稻中大苗。结果表明,该技术能在夏季高温多雨条件下,省工节本地控制苗床温湿度,以利于秧苗旱育生长。旱育秧的叶龄、苗高、干重和单株分蘖数与同期水秧相近;苗高比水秧矮1/3;栽后3d发根数比水秧多50%。  相似文献   

20.
为了查明黑河地区大豆胞囊线虫的分布,对2010和2011年采集的黑河地区96份大豆田土样进行调查,研究了黑河地区大豆胞囊线虫的种群密度。结果表明:黑河地区采集的土样均发现大豆胞囊线虫,且其胞囊密度分布不均匀。将黑河地区各点连续2a采集得到每100g风干土中胞囊数量分为5个区段:胞囊密度为0~50个的占13.79%,胞囊密度为50~100个的占37.93%,胞囊密度为100~150个的占17.24%,胞囊密度为150~200个的占27.57%,胞囊密度超过200个的占3.45%。  相似文献   

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