Experimental study of the spray characteristics of biodiesel based on inedible oil

We studied the spray characteristics of inedible oil using experimental and simulation methods. Spray penetration, spray cone angle and spray tip speed were measured at different biodiesel ratios in a constant volume vessel with wide visualization and high back pressure, using a high-speed camera. The characteristics of biodiesel spray were simulated under the same conditions using Star-CD software. The experimental results showed that, as the ratio of biodiesel in the blends increased, spray penetration and spray speed increased, but the spray cone angle decreased. Throughout the spray injection period, the region at 0.05–0.475S (spray tip penetration) was a key area affecting spray cone angle. From 0.8 ms after injection, the spray penetration deviation ratios started to increase with increasing biodiesel blend ratios. Simulation results showed similar macroscopic spray characteristics to the experimental results for jatropha oil. The results also showed that the Sauter mean diameter of blend fuels was greater than that of diesel, and spray was more concentrated, due to the higher viscosity and surface tension of the biodiesel, compared with conventional diesel fuel. The macroscopic and microscopic spray properties of blended fuels containing 5%, 10% and 20% biodiesel were similar to diesel.     

RNA interference technology to improve the baculovirus-insect cell expression system

The baculovirus expression vector system (BEVS) is a popular manufacturing platform for the production of recombinant proteins, antiviral vaccines, gene therapy vectors, and biopesticides. Besides its successful applications in the industrial sector, the system has also played a significant role within the academic community given its extensive use in the production of hard-to-express eukaryotic multiprotein complexes for structural characterization for example. However, as other expression platforms, BEVS has to be continually improved to overcome its limitation and adapt to the constant demand for manufacturing processes that provide recombinant products with improved quality at higher yields and lower production cost.RNA interference, or RNAi, is a relatively recent technology that has revolutionized how scientist study gene function. Originally introduced as a tool to study biological and disease-related processes it has recently been applied to improve the yield and quality of recombinant proteins produced in several expression systems. In this review, we provide a comprehensive summary of the impact that RNAi-mediated silencing of cellular or viral genes in the BEVS has on the production of recombinant products. We also propose a critical analysis of several aspects of the methodologies described in the literature for the use of RNAi technology in the BEVS with the intent to provide the reader with eventually useful guidance for designing experiments.     

Overyielding in experimental grassland communities – irrespective of species pool or spatial scale

In a large integrated biodiversity project (‘The Jena Experiment’ in Germany) we established two experiments, one with a pool of 60 plant species that ranged broadly from dominant to subordinate competitors on large 20 × 20 m and small 3.5 × 3.5 m plots (= main experiment), and one with a pool of nine potentially dominant species on small 3.5 × 3.5 m plots (= dominance experiment). We found identical positive species richness–aboveground productivity relationships in the main experiment at both scales. This result suggests that scaling up, at least over the short term, is appropriate in interpreting the implications of such experiments for larger‐scale patterns. The species richness–productivity relationship was more pronounced in the experiment with dominant species (46.7 and 82.6% yield increase compared to mean monoculture, respectively). Additionally, transgressive overyielding occurred more frequently in the dominance experiment (67.7% of cases) than in the main experiment (23.4% of cases). Additive partitioning and relative yield total analyses showed that both complementarity and selection effects contributed to the positive net biodiversity effect.     

Variation in soil aluminium tolerance genes is associated with local adaptation to soils at the Park Grass Experiment

Studies of the wild grass Anthoxanthum odoratum at the long‐term Park Grass Experiment (PGE, Harpenden, UK) document a well‐known example of rapid plant evolution in response to environmental change. Repeated fertilizer applications have acidified the soil in some experimental plots over the past 150+ years, and Anthoxanthum subpopulations have quickly become locally adapted. Early reciprocal transplants showed subpopulation differentiation specifically in response to soil aluminium (Al) toxicity across the experiment, even at small (30 m) spatial scales. Almost 40 years after its original measurement, we reassessed the degree of local adaptation to soil Al at the PGE using updated phenotyping methods and identified genes with variation linked to the tolerance trait. Root growth assays show that plants are locally adapted to soil Al at both the seedling and adult growth stages, but to a smaller extent than previously inferred. Among a large suite of candidate loci that were previously shown to have Al‐sensitive expression differences between sensitive and tolerant plants, three loci contained SNPs that are associated with both Al tolerance and soil acidity: an Al‐sensitive malate transporter (ALMT), a tonoplast intrinsic protein (TIP) and the putative homolog of the rice cell‐wall modification gene STAR1. Natural genetic variation at these loci is likely to have contributed to the recent rapid evolution at PGE. Continued study of Al tolerance variants in Anthoxanthum will allow us to test hypotheses about the nature and source of genetic variation that enables some species to adapt to soil acidification and other types of rapid environmental change.     

Hands-on or Video-based Learning with ANTicipation? A Comparative Approach to Identifying Student Motivation and Learning Enjoyment During a Lesson about Ants

The observation of living animals in school laboratories provides authentic views of biological research. Various studies stress the importance of primary experiences in biology classes. However, educational films may serve as an alternative in some cases. The aim of this study was to investigate student motivation before and after treatments, including (1) an educational film, (2) a hands-on activity with living animals accompanied by an educational film and (3) a hands-on activity with living animals. We investigated the influence of teaching method, gender and class level on student motivation and learning enjoyment. In all treatments, Temnothorax ants were addressed, which can be easily kept and observed. This paper is within the scope of a longitudinal project based on the concept of ‘ant research’ in class. Students (N = 140) from six classes (lower and intermediate secondary school levels) participated in the study. Student motivation was measured using a two-stage test design, including a standardised questionnaire on current motivation and a test on learning enjoyment. The findings of this study suggest that the younger students prefer hands-on activities, while students at an intermediate secondary school level are more interested in video-based learning. Since the combination of hands-on activity and video yielded the best results, the potential of using videos as facilitators for hands-on learning is discussed.     

The thermal properties of some nests of the Eurasian Tree Sparrow Passer montanus

Using an electronic apparatus simulating a bird roosting in a nest at night, we examined the insulating qualities of Eurasian Tree Sparrow (Passer montanus) nests built in nest boxes under winter conditions. Nests of different construction were compared with an empty box, and with roosting in open air. Energy savings in an empty box accounted for 18%, in boxes with incomplete nests for 23% and in boxes with complete nests up to 36%. The insulating value of nests mostly depended on their completeness and the proportion of feathers in the lining.     

Design of compliance chamber and after-load in apparatus for cultured endothelial cells subjected to stresses

In order to create a hemodynamic environment that can simulate the physiological condition of arteries, an in vitro experiment apparatus was designed whose key modules were compliance chamber and after-load. These two modules were developed based on the theories of hemodynamics. Both the normal and shear stress to which endothelial cells are exposed can be controlled with these modules, thus facilitating the research of endothelial cells subjected to stresses.     

沂源上崖洞石制品的研究

本文记述了１９８１年在山东省沂源县上崖洞发现的石制品,并仿制了有关类型的石器,进行切削、刮和钻孔试验,然后用电镜和体视显微镜（ＯＬＹＭＰＵＳ ＳＺＨ－１５１）观察其使用微痕。通过实验标本和上崖洞的石器二者对比观察和分析,认为本文所记述的石器主要用于切割和钻孔。根据洞内地层堆积,可以确定上岩洞石制品的时代晚期。     

Experimental ecology of rocky intertidal habitats: what are we learning?

Experimental analyses of causes of patterns of distribution and abundance of intertidal animals and plants on rocky shores have been a major activity for many years. In this review, some of the themes and topics that have emerged from such analyses are briefly discussed to provide an up-date for practitioners and ecologists working in other habitats. Conceptual issues include the widespread occurrence of transphyletic use of the same resources (space and food), theories and experimental analyses of intermediate disturbance in relation to numbers of species, the complex but pervasive nature of indirect interactions among species, relative importance of ‘top-down’ versus ‘bottom-up’ control of assemblages and the importance to rocky intertidal species of ‘supply-side’ influences on densities and interactions. Methodological advances include experimental designs for complex and patchy, interacting sets of species, the importance of controls in experimental manipulations and methods for analyses of hierarchical scales of patterns and processes. Finally, some contributions to social issues (pollution, biodiversity) and some scenarios for future directions are briefly considered.