军都山古代人群牙齿磨耗及其饮食

以军都山墓地为代表的"玉皇庙文化"系中国北方青铜时代的一支具有鲜明地方特色的少数部族文化。本文对军都山墓地出土人骨牙齿标本作牙齿磨耗状况分析,试图为其饮食结构和社会经济形态的探讨提供线索。结果显示:军都山古代人群中,相同年龄组的男女两性牙齿磨耗差异不大;前部牙齿磨耗轻于后部臼齿,第一臼齿磨耗最重;臼齿磨耗样式大多呈现"正常平匀"式,臼齿磨耗角度大多较小,两者均随年龄而变化但没有显著的性别差异。经与其他样本组的对比认为军都山古代人群牙齿磨耗的特点可能与其社会经济农牧兼营的性质有关,推测动物性食物(肉食)可能在军都山古代人群主要饮食结构中占据重要比例,并包含有一定的农业经济成分。不同游牧人群牙齿磨耗程度差异较大,只有结合了磨耗形态及其他信息才有可能更切实地反映其饮食状况。     

军都山古代人群运动模式及生活方式的时序性变化

古代畜牧生计人群的生活方式、对畜牧业依赖程度及与相邻定居人群的关系表现多样。军都山墓地是东周时期以畜牧业为重要生计方式的玉皇庙文化代表性遗址,在其延续的近三百年时间里文化遗存发生了一些明确变化,暗示其生活模式的可能改变。本文通过该遗址出土人骨体质状况的表现对军都山古人群运动和生活方式的时序性变化进行探讨。106根股骨骨干中部断面生物力学参数被用来分析其下肢功能状况及流动性,2487枚牙齿的龋病发生情况用于了解其植物性食物摄入的变化趋势。结果表明,与放牧生活密切相关的流动性在男性随时代明显减弱,但一直显著高于同性别农业定居人群;女性的流动性则变化不大,与定居农业人群相当。龋齿发病在男性随时代显著增高,女性则变化不明显且维持在相对较高水平,表明男性饮食中粮食类占比随时代有增加的趋势。结合文化遗存的发展变化推断,虽然畜牧业一直是军都山古代人类最重要的生计模式,但其流动性和龋病的变化表明畜牧业在其生业模式重要性随时代有所下降;伴随其的是农业在其经济生活中的比重开始增加,可能是受周边定居农业文化影响的结果。     

北京军都山古代居民的颅骨创伤

北京延庆军都山墓地是东周时期玉皇庙文化的代表性墓地。对墓地出土125例个体颅骨创伤的观察表明,军都山男性颅骨创伤的发生率为13.3%,均为生前钝器伤;女性和未成年个体则未发现有颅骨创伤病例。颅骨创伤的发生没有时代变化或墓葬等级间的差异。军都山古代男性居民较高的颅骨创伤率与暴力冲突关系最为密切,是军都山社会关系不稳定性的一种体现,与农牧交错区生态的脆弱性、外来人群流入以及与周边定居农业人群互动等因素所导致的竞争增强有关。     

Patterns of variability in mineralization of the primate femoral diaphysis.

The purpose of this research was to study intra- and interspecific variability in mineral density in the femoral diaphysis of nonhuman primates. Four hundred five sections were taken from five sites along the femoral diaphysis of 34 macaques (Macaca sp.), 24 squirrel monkeys (Saimirisciureus), and 23 tamarins (Saguinus labiatus). The mineral density at eight positions around each section was measured. Analysis of variance indicated significant (p less than 0.05) interactions among species, sex, cross sectional levels, and positions within each level. Both Macaca and S. sciureus showed sexually dimorphic patterns of mineral distribution. S. labiatus exhibited no sexual dimorphism in distribution, but was sexually dimorphic in density magnitude. No significant dimensional differences in density were found among species, though significant differences in pattern were evident. Highly significant differences (p less than 0.01) were found among cross sectional levels and among positions within the levels within each species.     

Perturbation analysis of the voltage-sensitive conformational changes of the Na+/glucose cotransporter

Conformational changes of the human Na(+)/glucose cotransporter (hSGLT1) were studied using voltage-jump methods. The cotransporter was expressed in Xenopus laevis oocytes, and SGLT1 charge movements were measured in the micro- to millisecond time scale using the cut-open oocyte preparation and in the millisecond to second time scale using the two-electrode voltage clamp method. Simultaneous charge and fluorescence changes were studied using tetramethylrhodamine-6-maleimide-labeled hSGLT1 Q457C. In 100 mM external [Na(+)], depolarizing voltage steps evoked a charge movement that rose initially to a peak (with time constant tau = 0.17 ms) before decaying to steady state with two time constants (tau = 2-30 and 25-150 ms). The time to peak (0.9 ms) decreased with [Na(+)], and was not observed in 0 mM [Na(+)]. In absence of Na(+), charge movement decayed monotonically to steady state with three time constants (0.2, 2, and 150 ms). Charge movement was accompanied by fluorescence changes with similar time courses, indicating that global conformational changes monitored by charge movement are reflected by local environmental changes at or near Q457C. Our results indicate that the major voltage-dependent step of the Na(+)/glucose transport cycle is the return of the empty carrier from inward to outward facing conformations. Finally, we observed subtle differences between time constants for charge movement and for optical changes, suggesting that optical recordings can be used to monitor local conformational changes that underlie the global conformational changes of cotransporters.     

Early ontogeny of the human femoral bicondylar angle

The presence of a femoral bicondylar angle consistently and significantly greater than 0° has been a hallmark of hominid bipedality, but its pattern of development has not been documented. We have therefore compiled cross-sectional data on the development of the articular bicondylar angle for a clinical sample of modern humans and of the metaphyseal bicondylar angle for two Recent human skeletal samples, one predominantly European in origin and the other Amerindian. All three samples exhibit a pattern of a bicondylar angle of 0° at birth and then a steady average increase in the angle from late in the first year postnatal, through infancy, and into the juvenile years. The two skeletal samples reach low adult values by approximately 4 years postnatal, whereas the clinical sample with a lowered activity level appears to attain consistent adult values slightly later (approximately 6 years postnatal). In addition, two modern human individuals, one nonambulatory and the other minimally ambulatory, show no and little development, respectively, of a bicondylar angle. These data, in conjunction with clinical and experimental observations on the potential and form of angular changes during epiphyseal growth, establish a high degree of potential for plasticity in the development of the human bicondylar angle and the direct association of a bipedal locomotion and (especially) posture with the developmental emergence of a human femoral bicondylar angle. © 1994 Wiley-Liss, Inc.     

石羊河尾闾绿洲的景观变化与生态恢复对策

利用G IS技术和景观结构分析软件FRAG STATS,在对民勤湖区绿洲景观格局动态变化以及土地利用格局的空间转化分析的基础上,从水资源利用以及政策和市场经济等方面分析了湖区景观变化的驱动因素,结果表明:(1)耕地和沙地斑块数量减少,平均斑块面积增加,空间连片趋势加剧;蔓延度指数变大,边缘密度和多样性指数降低;(2)沙地和耕地面积分别增加5171.85 hm2和2640.33hm2,它们的增加以牺牲林、草地为代价;(3)湖区地表水净利用量近10a来降幅达50%,到20世纪90年代后期仅有0.22×108m3,使得地下水净利用量近年来年均高达0.80×108m3;(4)以耐盐性较强的经济作物占绝对优势的单一经济结构,降低了农业生产对市场风险的抵御能力,农户收入急剧下降。通过以上分析,提出了湖区生态恢复途径与措施。