New insights on the loess/paleosol Quaternary stratigraphy from key sections in the U.S. Midwest

Three key Quaternary loess/paleosol sections were examined in the Missouri Valley (Iowa), Eustis Ash Pit (Nebraska), and in the Wittsburg Quarry (Arkansas) to gain insights into the sedimentation, environment and climate change of the U.S. Midwest. Four loess units are present separated by three well-developed paleosols. Crowley's Ridge Loess (Oxygen Isotope Stage (OIS) 8) is pre-Illinoian in age, and is the oldest loess unit investigated. A well-developed paleosol, interpreted as Yarmouth Soil (OIS 7), is found in this loess in all three sections. Overlying the Yarmouth Soil is Loveland Loess (OIS 6) which has been pedogenically altered by the Sangamon Soil (OIS 5). It has luvisolic properties but a more clayey pedogenic texture than modern luvisols and has no clear eluvial horizon. The overlying Roxana Silt (OIS 4) is pedogenically altered. At Wittsburg and Missouri Valley, the Farmdale Soil (OIS 3) is developed in the Roxana Silt. Based on pedogenic features, we correlate this paleosol to that developed in the Gilman Canyon Formation at Eustis. In Missouri Valley and Eustis sections, the paleosol has chernozemic properties and therefore, the gleyic features observed at Missouri Valley are interpreted as later alterations. Overlying the Farmdale Soil is the widespread Peoria Loess (OIS 2).     

Self-assembly of large and small molecules into hierarchically ordered sacs and membranes

We report here the self-assembly of macroscopic sacs and membranes at the interface between two aqueous solutions, one containing a megadalton polymer and the other, small self-assembling molecules bearing opposite charge. The resulting structures have a highly ordered architecture in which nanofiber bundles align and reorient by nearly 90 degrees as the membrane grows. The formation of a diffusion barrier upon contact between the two liquids prevents their chaotic mixing. We hypothesize that growth of the membrane is then driven by a dynamic synergy between osmotic pressure of ions and static self-assembly. These robust, self-sealing macroscopic structures offer opportunities in many areas, including the formation of privileged environments for cells, immune barriers, new biological assays, and self-assembly of ordered thick membranes for diverse applications.     

Exogenous DNA Uptake of Boar Spermatozoa by a Magnetic Nanoparticle Vector System

The sperm‐mediated gene transfer method is applicable to transgenesis in many species that use spermatozoa for reproduction recently, which has been shown various results. In the current study, we show that transgenic porcine embryos can be efficiently produced by employing a simple transfection method that uses magnetic nanoparticles (MNPs). The complexes formed between plasmid DNA and MNPs were bounded on ejaculated boar spermatozoa at a higher efficiency compared to methods using DNA alone or lipofection. Using confocal microscopy, rhodamine fluorophore‐labelled MNPs were detected on external surfaces of the spermatozoa membrane, which were bounded on zona pellucida of in vitro maturated oocyte during in vitro fertilization. Electron microscopy revealed that clusters of MNPs were detected in inside of plasma membrane and nucleus of the spermatozoa head. Additionally, we found that magnetofected boar spermatozoa could be fertilized with oocytes in vitro and that the resulting gene of green fluorescent protein was detected in fertilized eggs by genomic PCR analysis. Taken together, these results suggest that MNPs can be used to efficiently introduce a transgene into embryo via spermatozoa.     

玉米杂交种辽单27号选育报告

1　亲本来源辽单 2 7号 (原名辽 940 4 )为辽宁省农业科学院作物研究所以自选系辽 2 30 9为母本 ,引入系丹340为父本杂交组配而成。辽 2 30 9自选系是 1 990年以美国先锋杂交种7861 3(ｏｐ)为基础材料连续自交多代选择育成。辽 2 30 9一般配合力高 ,高抗大、小斑病和丝黑穗病 ,抗病毒病和茎基腐病 ,秆硬抗倒 ,株形紧凑 ,活秆成熟 ,产量高。2　辽单 2 7号选育经过1 992年冬在海南岛测配时用丹 340 (是当时测验种之一 )配制成辽 2 30 9×丹 340杂交组合。1 993～ 1 994年进行院内品比试验。 1 995年参加辽宁省区域试验预备试验 ,1 996～ 1 997…     

Factors affecting the natural transmission of bovine leukaemia virus infection in Queensland dairy herds

Natural transmission of bovine leukaemia virus (BLV) infection in south-eastern Queensland dairy herds was slow in 2 herds with a low to moderate (13 to 22%) prevalence of infection. Infection spread much more rapidly in a herd that had a higher prevalence (42%) when first tested. In a 13 month study of this herd, the cumulative incidence of infection was 24%. In one herd new infections were confined almost entirely to calves of uninfected dams. Following the end of feeding bulk milk to calves, a common practice in dairy herds, no more calves in this herd became infected. In laboratory experiments, neither prolonged housing of susceptible calves with infected cattle, consumption of drinking water contaminated with infected blood, nor inoculation of sheep with saliva from infected cattle resulted in transmission of BLV infection. Sheep were infected by subcutaneous inoculation of a suspension of purified lymphocytes from an infected heifer. The minimum infective dose was 10(3) lymphocytes, equivalent to the number of lymphocytes in approximately 0.1 microliter blood. Thus, procedures involving the transfer of a very small volume of blood from animal-to-animal have the potential to transmit infection.     

Downstream fish migration from two regulated lakes monitored by hydroacoustics

The migration of fish from two large northern Finnish lakes to their outflowing rivers was studied by echosounding and exploratory fishing. Both lakes are regulated for hydroelectric purposes. In both rivers, two sonar stations with stationary up- and down-looking transducers were used to collect data for one year. The fish migration rate in the River Oulujoki was greater than in the River Paatsjoki. In the River Oulujoki, the fish migrated mainly downstream and in the River Paatsjoki both down- and upstream. In the River Paatsjoki, larger fish showed active migration in the spring and autumn, whereas in the River Oulujoki the increase in the migration occurred simultaneously in all size groups. The different species composition and the different nature of the lakes, together with the different regulation practices, were considered to be responsible for the varying migration patterns. It was concluded that no barriers to fish migration should be built on these rivers.     

Effect of Dietary N‐Carbamylglutamate Levels on Reproductive Performance of Gilts

The effect of dietary N‐carbamylglutamate (NCG) supplementation during the entire gestation on reproductive performance of gilts was determined. At the initial day of gestation, forty‐five cross‐bred (Landrace × Large white) gilts were randomly assigned to five groups receiving a basal diet (control group) and basal diet supplemented with 0.05%, 0.10%, 0.15% and 0.20% NCG until parturition, respectively. At parturition, total litter size, live litter size and rate of stillbirth were not markedly affected by NCG supplementation. However, gilts in 0.05% NCG‐supplemented group had more pigs born alive than gilts in control group (+1.11 pigs, p = 0.12), and live litter weight was increased (+12.13–19.17%, p < 0.05) in 0.05%, 0.10% and 0.15% NCG‐supplemented groups relative to control group. And also, average birthweight of piglets born alive was higher (+6.57%, p < 0.05) in 0.05% NCG‐supplemented group than in control group. Furthermore, on days 30, 60, 90 and 110 of gestation, concentrations of arginine and ornithine in plasma were higher (p < 0.05) in 0.05%, 0.10%, 0.15% and 0.20% NCG‐supplemented groups than in control group, respectively. In addition, the chorioallantois gene expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor A (VEGF‐A), placental growth factor (PLGF) and angiopoietin‐2 (ANG‐2) was all increased (p < 0.05) in 0.05%, 0.10% and 0.15% NCG‐supplemented groups than in control group. In conclusion, dietary supplementation with 500 mg/kg NCG during the entire gestation significantly improves pregnancy outcomes in gilts, which may be associated with the improved concentrations of arginine in plasma and placental angiogenic factors gene expression of gilts.     

Parthenogenetic Induction of Canine Oocytes by Electrical Stimulation and Ca-EDTA

In this study, we investigated parthenogenetic induction of canine oocytes by electrical stimulation following Ca-EDTA treatment. Oocyte maturation, parthenogenetic development, and cleavage rate in canine after various electrical stimulations (1.5, 1.8, 2.1 kV/cm) for 50 μs with single DC pulse following 1 mM Ca-EDTA treatment were investigated. In oocyte activated electrically at the voltage of 1.5 kV/cm after 1 mM Ca-EDTA treatment, the rate of pronucleus and two-cell was 4.1% and 2.7%, respectively. Although electrical stimulation could parthenogenetically induce immature oocyte to cleavage stage, degeneration rate in all experimental groups was more than 60%. This means that electrical stimulation after Ca-EDTA treatment could cause canine oocytes to be degenerated. However, two-cell in canine oocyte by parthenogenesis was for the first time induced. Therefore, we suggested that electrical stimulation for canine oocytes could induce parthenogenetically early embryonic cleavage. This result can be used as a basic data for parthenogenesis study in canine. Also, to perform more developed embryonic development, further study to parthenogenesis in canine need to be developed.     

Basic features of late pleistocene soil formation in the east european plain and their paleogeographic interpretation

Large-scale climate fluctuations reflected in the alternation of glacial and interglacial epochs have resulted in structural changes in the landscape shell. Differences in heat and moisture supply have accounted for specific features of soil-forming processes, zonality structure, and the ratio of soil formation and sedimentation processes. The sequence of types of soil formation epochs is most completely reflected in the structure of loess-soil cryogenic formations, where specific features of soil formation and sedimentation during no less than seven natural climatic macrocycles (over the past 800 ka, the Brunhes paleomagnetic epoch) have been revealed and analyzed. Within macrocycles, three main types of soil formation epochs have been distinguished: interglacial, interstadial, and pleniglacial (interphasial). Interglacial soil formation evolved from subtropical in the Eopleitocene and Early Pleistocene to subboreal and boreal in the Middle and Late Pleistocene. Interstadial dark-colored soils developed during early interstadial warmings at the beginning of glacial epochs and formed complexes with interglacial soils. Pleniglacial soil formation was characteristic of the coldest phase of the Valdai glaciation, when sedimentation and physical weathering absolutely prevailed over soil formation, leading to the development of specific synlithogenic soils. In the periods of climate softening, interstadial soils of cryo-gley genesis were formed.