On dental wear, dental work, and oral health in the type specimen (LB1) of Homo floresiensis

The claim that the lower left first mandibular molar of LB1, the type specimen of Homo floresiensis, displays endodontic work, and a filling is assessed by digital radiography and micro-CT scanning. The M(1) tooth crown is heavily worn and exhibits extensive dentine exposure that is stained white, but there is no trace of endodontic treatment or a dental filling in this Indonesian fossil dated to 17.1-19.0 kya. Dental calculus (commonly observed in foragers) is present on the teeth of LB1, but there are no observable caries. The pattern of dental attrition in the mandibles of both LB1/2 and LB6/1 (moderate to extensive flat wear across the entire arch) is consistent with that seen in Plio-Pleistocene Homo fossils and in modern hunter-gatherers, and is not typical of most agriculturalists. We conclude that the dental-work and farming hypotheses are falsified and therefore irrelevant to the debate over the taxonomy and phylogeny of H. floresiensis.     

Fight tactics in wood ants: individuals in smaller groups fight harder but die faster

When social animals engage in inter-group contests, the outcome is determined by group sizes and individual masses, which together determine group resource-holding potential ('group RHP'). Individuals that perceive themselves as being in a group with high RHP may receive a motivational increase and increase their aggression levels. Alternatively, individuals in lower RHP groups may increase their aggression levels in an attempt to overcome the RHP deficit. We investigate how 'group RHP' influences agonistic tactics in red wood ants Formica rufa. Larger groups had higher total agonistic indices, but per capita agonistic indices were highest in the smallest groups, indicating that individuals in smaller groups fought harder. Agonistic indices were influenced by relative mean mass, focal group size, opponent group size and opponent group agonistic index. Focal group attrition rates decreased as focal group relative agonistic indices increased and there was a strong negative influence of relative mean mass. The highest focal attrition rates were received when opponent groups were numerically large and composed of large individuals. Thus, fight tactics in F. rufa seem to vary with both aspects of group RHP, group size and the individual attributes of group members, indicating that information on these are available to fighting ants.     

掌叶大黄根多糖的积累分布特征

采用组织化学方法和苯酚硫酸比色法研究了掌叶大黄（Rheum palmatum）根中大黄多糖的贮藏分布特征和含量变化规律。结果表明：大黄多糖在根内的贮藏是多位点的,在根周皮的栓内层、次生维管组织的薄壁细胞内不同程度地贮藏和积累了一定数量的大黄多糖,次生木质部的木薄壁细胞和次生韧皮部的韧皮薄壁细胞是主要贮藏和积累的部位;不同发育时期根中大黄多糖含量的变化规律为,随着植物的不断成熟,根及其各组织中大黄多糖的总含量表现为逐渐增高的趋势,但在发育的后期略有下降;韧皮薄壁细胞与木薄壁细胞相比,贮藏大黄多糖的含量相对较多,大黄多糖的贮藏积累方式为逐渐累积的方式。     

掌叶大黄茎和叶多糖的贮藏分布特征

采用组织化学方法和苯酚硫酸比色法研究了掌叶大黄茎和叶中大黄多糖的分布特征和含量变化规律.结果表明:大黄多糖在掌叶大黄茎和叶内的分布各有特点,在茎中大黄多糖分布于靠近维管束外方的皮层薄壁细胞、维管束的韧皮薄壁细胞、靠近皮层的髓射线细胞和少数髓细胞,皮层和髓射线是茎中大黄多糖贮藏较集中的部位,且随着茎的成熟其含量有一定程度的增加;在叶的表皮、叶肉和叶脉中不同程度地分布着较少量的大黄多糖;大黄多糖在叶柄维管束外围的基本组织细胞中不同程度地分布较多,而维管束中分布较少.茎和叶中大黄多糖的含量每年在植物生长的前期逐渐增高,后期略有下降.     

Dental health indicators of hunter-gatherer adaptation and cultural change in Siberia's Cis-Baikal

This investigation of the Cis-Baikal dental record focuses on health and lifestyle reconstruction of the region's mid-Holocene foragers, with particular interest in an apparent fifth millennium BC biocultural hiatus. The four cemetery populations considered represent two distinct biological and cultural groups separated by an apparent 700-year hiatus: the late Mesolithic-early Neolithic Kitoi culture (6800-4900 BC) and the middle Neolithic-early Bronze Age Serovo-Glaskovo cultural complex (4200-1000 BC). Research focuses on the frequency and severity of seven dental health indicators: enamel hypoplasia, caries, alveolar defects, periodontitis, antemortem tooth loss, dental calculus, and dental attrition. Together, these seven indicators provide a basis not only for better understanding mid-Holocene lifeways in the Cis-Baikal but also for independently assessing the relative effectiveness of the different adaptive strategies employed by pre- and posthiatus peoples. Results reveal some discrepancies between the Kitoi and Serovo-Glaskovo, specifically in their relative vulnerability to physiological stress, providing evidence to support previous interpretations of their distinct adaptive regimes (namely the narrower resource base and decreased mobility of the former). Results also suggest that some of the differences observed among the four sites may reflect geographical or environmental factors rather than simply cultural ones. However, despite these distinctions, the overriding trend appears to be one of general continuity, social equality, and good health among all mid-Holocene occupants of the Cis-Baikal, pre- and posthiatus alike.     

Mothers’ caregiving during COVID: The impact of marital property laws on women’s labor force status

If mothers take care of children more than fathers, then after the onset of COVID-19 mothers’ employment is expected to drop more than that of fathers. This gender gap is likely to be larger where women are less concerned about the financial repercussions of opting out of the labor force, and therefore the gender gap in employment is likely to grow more where community property or homemaking provisions give more protection to homemakers in case of union dissolution. Difference-in-differences and dynamic study estimations applied to CPS data for 2019–2020 show that after the onset of COVID-19 the labor force participation of mothers of school-age children—but not of fathers--dropped more in states with marital property laws more generous to parental caregivers. These results stand in contrast to how these groups’ labor force participation changed after the Great Recession, compared to pre-recession levels.     

The dynamic evolution of the power exponent in a universal growth model of tumors

We have previously reported that a universal growth law, as proposed by West and collaborators for all living organisms, appears to be able to describe also the growth of tumors in vivo after an initial exponential growth phase. In contrast to the assumption of a fixed power exponent p (assumed by West et al. to be equal to 3/4), we propose in this paper a dynamic evolution of p, using experimental data from the cancer literature. In analogy with results obtained by applying scaling laws to the study of fragmentation of solids, the dynamic behaviour of p is related to the evolution of the fractal topology of neoplastic vascular systems. Our model might be applied for diagnostic purposes to mark the emergence of an efficient neo-angiogenetic structure if the results of our in silico experiments are confirmed by clinical observations.     

姜黄在理血方剂中的配伍规律及系统药理机制分析

姜黄可以有效治疗各种疾病,本研究使用广义规则归纳(GRI)算法分析了《中药方剂大词典》中含姜黄的理血方剂配伍规律.通过利用生物信息学数据挖掘技术和MTT、Elisa和Western blotting实验验证了姜黄关键配方的系统药理机制.发现"姜黄-川芎-当归"配方可以代表姜黄在理血方剂中的关键组方.PPI网络和KEGG...