芜湖地区青少年儿童皮下脂肪及身体围度发育规律初探

分析了安徽省芜湖地区1217名城乡在校中小学生四项皮褶厚度及四项身体围度随年龄变化的规律,尤其是青春期的变化;以及营养、气候等环境因素对儿童青少年身体发育的影响。结果表明：在即将进入青春发育期时,男性四肢部皮下脂肪迅速减少;女性皮下脂肪在青春期迅速增厚;身体围度则随年龄增长而增加,在青春后期,围度保持在一定水平。     

冬小麦农田中净辐射的研究

本文对陕西泾阳地区冬小麦田净辐射进行了分段和分层模拟,取得了较好的拟合效果,相对误差在１０％以内。确定了麦田相对叶面积函数最大值的出现高度为４．５／７Ｈ,介于高粱（４／７Ｈ）和谷子（５／７Ｈ）之间。计算了不同发育期、不同层次至冠层顶部累积叶片的消光系数,结果表明,消光系数因发育期和叶片层次而异,拔节期,由旗叶向下,消光系数增大,乳熟期旗叶的消光系数最大,比拔节期大一倍,倒二叶以上两个层次叶片消光系数较小。就平均而言,冬小麦消光系数拔节期为０．５１,乳熟期为０．５６。本项成果为进一步开展麦田小气候研究提供了有意义的数据和方法。     

Porites growth characteristics in a changed environment: Misima Island, Papua New Guinea

 The construction in 1988 of an open-cut gold mine and ore-processing facility at Misima Island, Papua New Guinea, resulted in disturbance of the adjacent fringing coral reef, mostly because of large increases in sedimentation. This provided an opportunity to examine whether growth characteristics of the major reef-building coral, Porites, changed in response to this sudden and sustained increase in sedimentation. Annual variation in skeletal density was measured in 93 colonies variously affected by sedimentation. The colonies provided data for average annual density, annual extension and annual calcification covering the periods 5 y before and 5 y after mining operations began. The average depth of skeleton occupied by tissue (tissue layer thickness) was also measured for most colonies. There was high mortality of Porites in regions strongly affected by increased sedimentation. In colonies that survived, density, extension and calcification tended to be less (in some cases significantly) in the period after mining operations began compared with pre-construction levels. However, these decreases were not linked with proximity to the mine site and probably reflect a regional-scale response of Porites growth to some other environmental change. This suggests that periods of high sedimentation may not be recorded by the growth characteristics of massive Porites. Average growth characteristics of surviving Porites from Misima Island were similar to those from inshore reefs of the northern Great Barrier Reef (GBR). Tissue layer thickness in Porites from the control areas at Misima Island were also similar to colonies from the northern inshore GBR reefs. However, tissue layer thickness significantly decreased with increased proximity to the mine site at Misima Island. Accepted: 15 May 1999     

Global diversity and adaptations of avian eggshell thickness indices

The amniote eggshell is a fundamental aspect of the embryo life-support system, protecting it from UV light, microbes and mechanical damage, while regulating gas exchange and providing calcium for growth. The thickness of eggshells is highly diverse across modern birds and influences multiple eggshell functions, yet the selective pressures driving eggshell thickness have not been clearly identified. Here, we use a global dataset of avian eggshell thickness indices for 4260 (> 41%) avian species to assess trends in eggshell thickness across the phylogeny, as these indices are strongly correlated with direct measures of eggshell thickness and are non-destructive to the sample. We analysed the dataset within a phylogenetic framework to assess the relative importance of climatic and ecological explanations for variation in eggshell thickness indices. The distribution of avian eggshell thickness indices across species was found to be primarily driven by phylogenetic relatedness, in addition to evolutionary processes that do not match a Brownian model of evolution. Across modern birds, thicker eggshells were more prevalent in species (1) with precocial young, (2) which exhibit a scavenger-based diet, (3) which primarily feed on vertebrates or plants (excluding nectivores, seed and fruit specialists) and (4) which breed in open habitats. Thicker eggshells found in species with precocial young probably enable higher rates of calcium removal for the more advanced embryo development. Excessive light transmission through the shell damages developing embryos, while too little light transmission can impede development. Eggs in shaded habitats experience low light exposure, and thus thinner shells are more prevalent in these environments potentially to increase light transmission through the shell. Overall, variation in eggshell thickness indices appears to be driven largely by phylogeny, with certain life-history traits linked to embryo growth rate, calcium content of their food, and the need to mitigate excessive light transmission through the shell.     

Allometric patterns of cranial bone thickness in fossil hominids

The interspecific allometry of five measures of total cranial bone thickness is examined in 10 extant catarrhine genera and two fossil hominid samples representing A. africanus and Asian H. erectus. Analysis of the modern sample shows that most interspecific variation in vault thickness can be accounted for by variation in body size. Correlation values are moderate to high (r = 0.75–0.98), and all variables exhibit positive allometry. The bone thickness:body mass relationship of modern humans broadly conforms with that of other primates. However, in the distribution of relative thickness throughout the skull, H. sapiens is distinguished by relative thickening of the parietal and extreme relative thinning of the temporal squama. The bone thickness:body mass relationship in the two early hominid species is examined using published mean body weight estimates generated from post-cranial predictor variables. A. africanus exhibits great similarity to modern humans in its relation to the catarrhine regression data and in the distribution of relative thickness throughout the skull. H. erectus also shows a modern human-like pattern in the distribution of its relative thickness; however, its bone thickness:body mass relationship is dissimilar to that displayed by all other taxa, including the other hominid species. On the basis of these results, it is suggested that the published body weight estimate assigned to H. erectus greatly underestimates actual mean body size for Asian members of this species. © 1996 Wiley-Liss, Inc.     

季节性雪被对天山雪岭云杉凋落叶分解和碳氮磷释放的影响

季节性雪被下显著的冻融格局差异可能对干旱区山地森林凋落叶分解过程产生重要影响, 但一直未见深入研究。2015年10月至2016年10月, 采用凋落物分解袋法, 研究了天山典型树种雪岭云杉(Picea schrenkiana)凋落叶在季节性雪被覆盖下的3个关键时期(冻融期、深冻期、融冻期)以及生长季(生长季早期和生长季末期)的分解动态和碳、氮、磷释放特征。结果表明: (1)经过一年的分解, 不同雪被厚度下雪岭云杉凋落叶分解率为24.6%-29.2%, 且存在显著性差异。分解系数k值厚雪被覆盖最大, 无雪被覆盖最小。(2)冬季雪被覆盖期雪岭云杉凋落叶分解对当年分解总量的贡献达46.0%- 48.5%, 其中对冻融期凋落叶分解影响较为明显。(3)随着凋落叶的分解, 雪岭云杉凋落叶氮含量总体呈增加趋势; 碳含量和碳氮比大致呈下降趋势, 在深冻期和生长季末期不同雪被处理下碳含量呈显著性差异; 而凋落叶磷含量呈不规则变化趋势, 且在冻融期和融冻期不同雪被厚度下呈显著性差异。(4)整个雪被覆盖季节凋落叶氮元素表现为富集, 碳和磷元素表现为释放; 其中, 在融冻期薄雪被和中雪被处理下碳元素富集率最大, 在冻融期薄雪被、中雪被和厚雪被处理下, 融冻期无雪被和厚雪被下以及生长季早期中雪被和厚雪被下氮元素富集率最大, 而雪被对凋落叶磷释放的影响不显著。     

The effects of grooming on a copper ablative coating: a six year study

More than 90% of US Navy Ships are coated with copper ablative paint. These ships may spend long periods of time pier-side, which makes them vulnerable to fouling. Hull grooming has been proposed as a means of maintaining the coatings in an operational condition. This study investigated the effect of grooming on a copper ablative coating exposed statically for six years. Grooming was performed weekly or monthly with controls left ungroomed. The fouling community was visually assessed, dry film thickness measurements were taken to monitor coating loss, and the copper leaching rates were measured. It was found that weekly and monthly groomed surfaces reduced fouling, and the ungroomed surfaces became fully fouled. Coating loss was similar for weekly, monthly and ungroomed surfaces. The results suggest that grooming is a viable method for maintaining copper ablative coatings in a fouling-free condition without adverse increases in the total copper output.     

The point of a Guillemot's egg

The adaptive significance of avian egg shape in birds is poorly understood. The pyriform (pear‐like) shape of the Common Guillemot's Uria aalge egg has long been considered to be an adaptation to prevent eggs rolling off the bare cliff ledges on which this species breeds. Rolling was thought to be prevented either by the egg spinning like a top, which is not the case, or by rolling in an arc, which it does but with little influence on whether the egg will fall from a ledge. We therefore sought alternative explanations for the pyriform shape of the Common Guillemot's egg. This species breeds in extremely dense colonies, which makes their eggs vulnerable to mechanical damage from conspecifics, and to contamination by debris such as faeces and soil. We present evidence consistent with both these possible explanations. First, the pyriform shape of Common Guillemot eggs means that a higher proportion of the eggshell lies in contact with the substrate and this may minimize the effect of impacts. Resistance to impacts may be further enhanced because their eggshells are especially thick where they are in contact with the substrate. Secondly, Common Guillemot eggs are often heavily contaminated with faecal material and other debris during incubation. Most contamination is on the pointed end of the egg where it is in contact with the substrate; the pyriform shape thus keeps the blunt end of the egg, which has the highest porosity, relatively free of contamination, which in turn may facilitate both gas exchange during incubation and the hatching process, because the chick emerges from the blunt end of the egg.     

Cortical bone mapping: An application to hand and foot bones in hominoids

Bone form reflects both the genetic profile and behavioural history of an individual. As cortical bone is able to remodel in response to mechanical stimuli, interspecific differences in cortical bone thickness may relate to loading during locomotion or manual behaviours during object manipulation. Here, we test the application of a novel method of cortical bone mapping to the third metacarpal (Mc3) and talus of Pan, Pongo, and Homo. This method of analysis allows measurement of cortical thickness throughout the bone, and as such is applicable to elements with complex morphology. In addition, it allows for registration of each specimen to a canonical surface, and identifies regions where cortical thickness differs significantly between groups. Cortical bone mapping has potential for application to palaeoanthropological studies; however, due to the complexity of correctly registering homologous regions across varied morphology, further methodological development would be advantageous.     

High‐Sensitivity C‐Reactive Protein in Japanese Patients with Type 2 Diabetes

Objective: To assess the relationship between high‐sensitivity (HS) C‐reactive protein (CRP) and metabolic syndrome (MetS) or atherosclerosis and to assess effects of strict metabolic control on the degree of inflammation and MetS in patients with type 2 diabetes. Research Methods and Procedures: Four hundred thirteen patients with diabetes were enrolled in the cross‐sectional study. Of these 413 patients, 161 patients were further admitted for 2.4 ± 0.4 weeks (mean ± SD) to investigate the change in HS‐CRP or other parameters under strict metabolic control. Results: Log‐transformed HS‐CRP value (log HS‐CRP) was strongly correlated with BMI (r = 0.448, p < 0.01). Log HS‐CRP was also correlated with the presence of MetS or each component of MetS. Furthermore, a positive significant trend in HS‐CRP levels was shown with an increasing number of MetS components (p < 0.05). Log HS‐CRP showed a significant positive correlation with carotid artery intima‐media thickness (IMT) (r = 0.152, p < 0.01). In multiple step‐wise regression analysis, BMI, hemoglobin A_1c, right IMT, duration of diabetes, and triglyceride were selected as explanatory variables for log HS‐CRP (R² = 0.412). Under strict metabolic control, HS‐CRP was significantly (p < 0.01) lower, together with lower levels of other markers for MetS. The change in HS‐CRP was significantly correlated with the change in BMI (r = 0.161, p = 0.04). Discussion: In subjects with type 2 diabetes, HS‐CRP levels are related to MetS and subclinical atherosclerosis. Strict weight management and metabolic control were associated with a reduction in HS‐CRP levels, and changes in HS‐CRP were related to changes in weight, supporting the hypothesis that lifestyle modification reduces inflammation and the risk of CHD.