Glucose metabolism in vivo in crossbred Holstein cattle feeding on different types of roughage during late pregnancy and early lactation

An experiment was carried out to study the glucose kinetics of crossbred Holstein cattle feeding on either hay or 5% urea treated rice straw during late pregnancy (21 days prepartum) and early lactation (30 days postpartum). In all 16 pregnant heifers (23–25 months of age) were selected for the experiments, including eight animals of two breed types, Holstein Friesian×Red Sindhi (50:50=50% HF) and Holstein Friesian×Red Sindhi (87.5:12.5=87.5% HF). They were divided into four groups of four animals each. Animals from the same breed type in each group were fed with either rice straw treated with 5% urea or pangola hay (Digitaria decumbens) as the source of roughage throughout the experiments. The glucose turnover rate in both types of crossbred Holstein cattle was determined using a continuous infusion of [U-¹⁴C] and 3-[³H]glucose during late pregnancy and early lactation. Total glucose entry and utilization rates increased significantly during lactation for all groups. Recycling of [C]glucose was, approximately, 20% in both crossbred cattle fed either hay or urea treated rice straw and was unaffected by the stage of late pregnancy or early lactation. Comparing 50 and 87.5% HF animals, arterial plasma glucose concentrations were slightly higher during pregnant periods but significantly higher in lactating periods in 50% HF animals. The ratio of specific radioactivity of arterial blood bicarbonate relative to that of arterial blood [¹⁴C]glucose in the lactating period, significantly decreased in 50% HF animals fed either urea treated rice straw or hay. An increase in udder blood flow during early lactation was significantly higher in 87.5% HF animals than in 50% HF animals. The uptake, arteriovenous differences and extraction ratio for glucose across the udder, significantly increased in the lactating period for all crossbred animals. Glucose uptake by the udder of 87.5% HF animals accounted for 65% of the total glucose turnover rate compared to a value of 46% in the lactating 50% HF animals. It can be concluded that both crossbred cattle fed either urea treated rice straw or hay exhibit the same body glucose turnover rate. The 87.5% HF animal has the genetic potential for a high milk yield and has high body and udder glucose metabolisms compared with 50% HF animals.     

粘虫核型多角体病毒一个新基因的序列和结构研究

本文报道ＴｓＮＰＶＤＮＡＥｃｏＲＶ／ＸｈｏＩ的５．５ｋｂ片段的克隆及其物理图谱。测定了其中一个８１９ｂＰ片段的全序列。在长３４６ｂｐ的完整ＯＲＦ的５’端除有ＴＡＴＡｂｏｘ和ＣＡＡＴｂｏｘ以外,还发现有典型的早期基因启动子元件ＡＣＧＴ和ＧＣ单元以及晚期基因的转录起始保守序列ＴＴＡＡＧ。预测的ＯＲＦ产物为１１４个氨基酸、分子量为１３ｋＤ的蛋白质,故命名为ｐ１３蛋白。在ｐ１３基因的Ｃ端和Ｎ端分别有一个亮氨酸拉链和两个类亮氨酸拉链结构（我们称为亮氨酸转型结构和ＬＶＴ重复结构〕．从终止密码起有一个双发卡环结构,ｐ１３基因的５’端调控单元及其排列与ＢｍＮＰＶ和ＡｃＮＰＶ的细胞序死抑制基因（ｐ３５）十分相似,但ｐ１３基因与已经发现的杆状病毒基因序列和氨基酸序列没有同源性．因此,这是一个新的早晚期基因,其调控元件可能具有重要功能。     

The O.H.7 (Olduvai Gorge, Tanzania) parietal fragments and their reconstruction: a reply to Wolpoff

Given Wolpoff's (1981) dimensions for lambda-bregma and biparietal breadth, it was possible to reconstruct a new version of the O.H.7 hominid parietals. The constraints of the anatomical features of the original parietal fragments plus Wolpoff's constraints from his own reconstruction, permit testing his claims as a hypothesis. By comparing the resulting distortion of Wolpoff's proposed reconstruction with that of the original reconstruction by Tobias, it is clear that the latter's is far superior to the former's, and that the cranial capacity of O.H.7 of roughly 700 ml is most probable.     

菱臼齿兽((犭亚)目、哺乳纲)耳区的骨骼结构

本文详细描述了菱臼齿兽耳区各个部分的基本结构;并指出了耳区结构与某些啮齿类的相似性,以及中耳鼓泡组成成份与戈壁(犭亚)兽(Anagale gobiensis)的区别。     

浙江东部馆头组一些坚叶杉新种

本文报道的Pagiophyllum属4新种,是在对它们的角质层构造进行了研究的基础上建立的,标本产自浙东新昌县苏秦村附近的馆头组,共生的植物化石尚有Ruffordia goepperti, Zamiophyllum buchianum, Pseudofrenelopsis parceTflogoso, P. papillosa, Cupressinocladus elegans等;另在苏秦村南面镜岭的相当层位中还找到双壳类化石Plicotounio(P.)zheijiangensts。这些化石都表明馆头组的地质时代为早白垩世。     

Are scale circuli deposited daily in juvenile weakfish,Cynoscion regalis?

Synopsis Scale circuli of juvenile weakfish,Cynoscion regalis, were counted to determine if deposition was daily. Scale circuli counts were precise with little variation between counts (99% of the two counts from an individual scale were identical, N = 3580). Tetracycline marked juveniles (N = 71) had mean scale circuli deposition rates that were daily up to 24 d after marked. Data from several sources suggest that daily deposition of weakfish scale circuli occurred over a relatively narrow size range, approximately 14.3 to 111.9 mm standard length, however it is during this time that juvenile weakfish occupy estuarine nursery areas, where growth, mortality, and survival may alter subsequent year class strength. The estimated upper size limit at which scale circuli were no longer daily occurred over a wide range (82–142 mm standard length), and additional research is required to further clarify the limits of size and age of daily circuli deposition.     

河北阳原岑家湾发现的旧石器

岑家湾地点的石制品埋藏在下泥河湾层棕红色粘土中,地质时代属早更新世,文化层可能低于小长梁和东谷坨,是泥河湾层内发现的又一处较重要的旧石器地点。岑家湾的石器仅刮削器一类,加工简单,显得粗糙、古朴。岑家湾的石制品均较细小,当属华北地区小石器文化传统。     

The Early Holocene treeline in the southern French Alps: new evidence from travertine formations

Aims The present paper concerns the analysis of macro‐remains (plant imprints) from high altitude travertine deposits dating back to the early Holocene (9800 BP ). Our results allow us to discuss treeline location and ecology, and to supplement previous data based on pollen from natural sediments and charcoal from natural soil. Location The travertine under study is located in the Queyras massif, in the southern French Alps, along the Italian border. The site is situated on a south‐facing slope. Methods The travertine deposit has been dated by ²³⁰Th/²³⁴U. Taxonomic identification of plant imprints was achieved by comparison of the morphology of fossil specimens with extant material. Results Imprints of Pinus uncinata (cones and needles), broad‐leaved trees (Betula cf. pubescens, Populus tremula and Salix spp.), and unidentified trunks have been found. The plant assemblage records the existence at a high altitude (2200 m) of shade‐intolerant vegetation at around 9800 BP. Our data indicate that the treeline limit was at least 100 m higher than previously thought. The morphological features of the travertine, the plant assemblage and trunk diameters indicate that during the travertinization process, vegetation around the site was probably dense with tall upright trees. Main conclusions Our data show that Pinus uncinata and broad‐leaved trees developed at 2200 m, while regional pollen analyses locate the treeline at lower altitudes. Different research methods appear to provide different results. Around 9800 BP tree regeneration and growth were made possible up to at least 2200 m a.s.l., probably as a result of warmer and wetter summers. Warmer conditions are inferred from the predicted increase in incoming solar radiation based on calculated orbital variations, and wetter conditions are inferred from the build‐up of the travertine.     

Capture Rates of Male Euglossine Bees across a Human Intervention Gradient, Chocó Region, Colombia1

Euglossine bees are important pollinators of lowland Neotropical forests. Compared to disturbed habitats, undisturbed ones have been previously characterized by higher abundance and diversity of euglossine bees. Most past studies have relied on chemically baiting male bees at single sites within habitats. Over a two‐year period, we employed a repeated‐measures design in which we sampled bees at multiple sites within three different habitat types, reflecting a mosaic of human disturbance (farm, secondary forest, and old logged forest). After 22 monthly samples, a total of 2008 male bees were captured, representing 31 species in five genera: 1156 at the farm (57.6%, 21 spp.), 505 in the secondary forest (25.1%, 27 spp.), and 347 in the old logged forest (17.2%, 21 spp.). Eighty‐one percent of the bees captured belonged to the five most abundant species: Eulaema cingulata, El. chocoana, Euglossa hansoni, Eg. ignita, and Eg. imperialis. These species differed significantly in capture frequencies among habitats. Eulaema cingulata, El. chocoana, and Eg. ignita were captured most frequently at the farm, while Eg. imperialis was most abundant in the secondary forest. In contrast, Eg. hansoni, the sole short‐tongued species among the five, was equally abundant in the two forest habitats but occurred rarely on the farm. Additionally, habitats differed in bee composition. The high capture rates for long‐proboscis species at the farm may have been due to their ability to extract nectar from flowers with long floral tubes, which probably occurred at a greater density on the farmed land than in the adjacent forests.     

Comparative microhabitat use of cyprinid larvae and juveniles in a lotic floodplain channel

Synopsis The microhabitat of six cyprinids in a braided side-channel of the Upper Rhône River, France, was studied June to September 1985, using point abundance sampling by electrofishing. Correspondence analysis of the samples-by-species data and Jacob&s electivity index (calculated from the availability and exploitation of eight environmental variables) revealed three groups of species: (1) Leuciscus cephalus and Alburnus alburnus, which used relatively similar microhabitat during both larval and 0 + juvenile development; (2) Rutilus rutilus, Leuciscus leuciscus and Chondrostoma nasus, which used different microhabitats as larvae but whose microhabitat overlapped notably during 0 + juvenile development; (3) and Gobio gobio, whose juvenile microhabitat overlapped only marginally with that of other 0 + juveniles (no data were available on larvae). Overlap in microhabitat use by 0 + juveniles increased notably during a period of reduced discharge, when the amount of available vegetal and ligneous structures decreased; while most species exploited the increased area of shallow waters, juvenile A. alburnus appeared to be the only species that exploited the deeper waters off the channel&s steeper banks. Although not quantified, numerous field observations of predation threat, particularly during the period of reduced discharge (which reduced the amount of cover), suggest that predation risk may influence the microhabitat use of young fishes. Compared with similar species in European lakes, the overlap in microhabitat use of these fluvial cyprinids appears to be more intensive.