Projected ecosystem impact of the Prairie Heating and CO2 Enrichment experiment

The Prairie Heating and CO2 Enrichment (PHACE) experiment has been initiated at a site in southern Wyoming (USA) to simulate the impact of warming and elevated atmospheric CO2 on ecosystem dynamics for semiarid grassland ecosystems. The DAYCENT ecosystem model was parametrized to simulate the impact of elevated CO2 at the open-top chamber (OTC) experiment in north-eastern Colorado (1996-2001), and was also used to simulate the projected ecosystem impact of the PHACE experiments during the next 10 yr. Model results suggest that soil water content, plant production, soil respiration, and nutrient mineralization will increase for the high-CO2 treatment. Soil water content will decrease for all years, while nitrogen mineralization, soil respiration, and plant production will both decrease and increase under warming depending on yearly differences in water stress. Net primary production (NPP) will be greatest under combined warming and elevated CO2 during wet years. Model results are consistent with empirical field data suggesting that water and nitrogen will be critical drivers of the semiarid grassland response to global change.     

Darwin's artificial selection as an experiment

Darwin used artificial selection (ASN) extensively and variedly in his theorizing. Darwin used ASN as an analogy to natural selection; he compared artificial to natural varieties, hereditary variation in nature to that in the breeding farm; and he also compared the overall effectiveness of the two processes. Most historians and philosophers of biology have argued that ASN worked as an analogical field in Darwin's theorizing. I will argue rather that this provides a limited and somewhat muddled view of Darwinian science. I say "limited" because I will show that Darwin also used ASN as a complex experimental field. And I say "muddled" because, if we concentrate on the analogical role exclusively, we conceive Darwinian science as rather disconnected from contemporary conceptions of "good science". I will argue that ASN should be conceived as a multifaceted experiment. As a traditional experiment, ASN established the efficacy of Darwin's preferred cause: natural selection. As a non-traditional experiment, ASN disclosed the nature of a crucial element in Darwin's evolutionary mechanics: the nature of hereditary variation. Finally, I will argue that the experiment conception should help us make sense of Darwin's comments regarding the "monstrous" nature of domestic breeds traditionally considered to be problematic.     

The French initiative on environmental information of mass market products

Context and goals of the initiative  

Following the “Grenelle de l’Environnement”, the French Parliament is currently discussing a project of law in which it is mentioned that environmental information of mass market products in France will be experimented on sale’s place. This experiment will begin from the 1st July 2011 and will last at least 1 year. After this experiment, the French parliament will assess the opportunity to generalise this information.     

Using provenance to manage knowledge of in silico experiments

This article offers a briefing in one of the knowledge management issues of in silico experimentation in bioinformatics. Recording of the provenance of an experiment-what was done; where, how and why, etc. is an important aspect of scientific best practice that should be extended to in silico experimentation. We will do this in the context of eScience which has been part of the move of bioinformatics towards an industrial setting. Despite the computational nature of bioinformatics, these analyses are scientific and thus necessitate their own versions of typical scientific rigour. Just as recording who, what, why, when, where and how of an experiment is central to the scientific process in laboratory science, so it should be in silico science. The generation and recording of these aspects, or provenance, of an experiment are necessary knowledge management goals if we are to introduce scientific rigour into routine bioinformatics. In Silico experimental protocols should themselves be a form of managing the knowledge of how to perform bioinformatics analyses. Several systems now exist that offer support for the generation and collection of provenance information about how a particular in silico experiment was run, what results were generated, how they were generated, etc. In reviewing provenance support, we will review one of the important knowledge management issues in bioinformatics.     

Assessment of the anti-biofouling potentials of a copper iodide-doped nylon mesh

We propose a copper iodide (CuI)-doped nylon mesh prepared using polyiodide ions as a precursor toward anti-biofouling polymer textile. The CuI-doped nylon mesh was subjected to the prevention of biofouling in marine environments. The attachment of the marine organisms was markedly inhibited on the CuI-doped nylon mesh surface until 249 days. Scanning electron microscopy-energy dispersive X-ray analysis indicated that copper compounds were maintained in the nylon mesh after the field experiment, although copper content in the nylon mesh was reduced. Therefore, the copper ions slowly dissolved from nylon mesh will contribute to the long-term prevention of biofouling. Furthermore, electron spin resonance analysis revealed the generation of reactive oxygen species (ROS) from CuI-doped nylon mesh after the field experiment. One of the possibilities for toxic action of copper ions will be the direct effect of Cu+ -induced ROS on biofilm forming on nylon mesh surface. The proposed polymer textile can be applied to fishing and aquafarming nets, mooring rope for ship, or silt fence to restrict polluted water in marine environments.     

Methods to test the interactive effects of drought and plant invasion on ecosystem structure and function using complementary common garden and field experiments

Abiotic global change drivers affect ecosystem structure and function, but how they interact with biotic factors such as invasive plants is understudied. Such interactions may be additive, synergistic, or offsetting, and difficult to predict. We present methods to test the individual and interactive effects of drought and plant invasion on native ecosystems. We coupled a factorial common garden experiment containing resident communities exposed to drought (imposed with rainout shelters) and invasion with a field experiment where the invader was removed from sites spanning a natural soil moisture gradient. We detail treatments and their effects on abiotic conditions, including soil moisture, light, temperature, and humidity, which shape community and ecosystem responses. Ambient precipitation during the garden experiment exceeded historic norms despite severe drought in prior years. Soil moisture was 48% lower in drought than ambient plots, but the invader largely offset drought effects. Additionally, temperature and light were lower and humidity higher in invaded plots. Field sites spanned up to a 10‐fold range in soil moisture and up to a 2.5‐fold range in light availability. Invaded and resident vegetation did not differentially mediate soil moisture, unlike in the garden experiment. Herbicide effectively removed invaded and resident vegetation, with removal having site‐specific effects on soil moisture and light availability. However, light was generally higher in invader‐removal than control plots, whereas resident removal had less effect on light, similar to the garden experiment. Invasion mitigated a constellation of abiotic conditions associated with drought stress in the garden experiment. In the field, where other factors co‐varied, these patterns did not emerge. Still, neither experiment suggested that drought and invasion will have synergistic negative effects on ecosystems, although invasion can limit light availability. Coupling factorial garden experiments with field experiments across environmental gradients will be effective for predicting how multiple stressors interact in natural systems.     

Preparation of biological samples in space: the experiment preparation unit

The Experiment Preparation Unit (EPU) is a facility that prepares biological samples for their upcoming experiment within Biolab (Columbus). For logistical reasons and to avoid the influence of the heavy launch loads and the microgravity environment before the actual initiation of the experiment, biological samples will be sent cryogenically frozen to the International Space Station. The Experiment Preparation Unit will prepare those samples by thawing and extracting the cryogenic fluid automatically after minimal crew intervention for set-up of the system. The EPU can be tele-operated directly from ground and consists of three major subsystems to guarantee its functionality: Functional Platform, Base and Control Panel.     

脲酶抑制剂氢醌的环境效应评价

本文根据用标记和非标记氢醌进行的模拟、盆栽和田间定位试验,结合国内外文献有关氢醌的环境常数,论述了氢醌在土壤-植物系统的去向和代谢途径、对土壤酶活性的影响及其环境效应。得出的结论是:作为脲酶抑制剂使用的微量氢醌(0.3—0.4％,与尿素重量比),不会从土壤中淋失和挥发,在土壤和植物中没有累积,对与碳、氮和磷转化有关的土壤酶活性很少影响。在土壤中,它将通过氧化、臭氧化和生物学降解,经由环断裂生成二元酸或参与腐殖物质的合成。在植物体内,主要通过糖苷化得到同化和利用。因此,氢醌作为脲酶抑制剂在农业生产中应用是安全的。     

Automated culture system experiments hardware: developing test results and design solutions

The experiment proposed by Prof. Ricci University of Milan is funded by ASI with Laben as industrial Prime Contractor. ACS-EH (Automated Culture System-Experiment Hardware) will support the multigenerational experiment on weightlessness with rotifers and nematodes within four Experiment Containers (ECs) located inside the European Modular Cultivation System (EMCS) facility..Actually the Phase B is in progress and a concept design solution has been defined. The most challenging aspects for the design of such hardware are, from biological point of view the provision of an environment which permits animal's survival and to maintain desiccated generations separated and from the technical point of view, the miniaturisation of the hardware itself due to the reduce EC provided volume (160mmx60mmx60mm). The miniaturisation will allow a better use of the available EMCS Facility resources (e.g. volume. power etc.) and to fulfil the experiment requirements. ACS-EH, will be ready to fly in the year 2005 on boar the ISS.     

DETECTION AND INTERPRETATION OF VARIATION WITHIN AND BETWEEN ASSESSORS IN SENSORY PROFILING

In this paper we discuss methods that can be used to evaluate the performance of sensory panels. In particular we concentrate on detection of variation within and among panelists. A systematic presentation of some simple, graphically oriented tools will be given. Interpretation aspects of the tools will be emphasized. The methods will be illustrated by computations from a sensory experiment based on 4 sausage products. The example demonstrates how the tools can be used to evaluate the reproducibility of the assessors and also how they can be used to detect different types of individual differences among the assessors.     

八年制医学生实验动物教学中的心理障碍分析及对策

本文总结了在八年制医学生实验动物学实验课教学中的一些体会,研究了教学过程中出现的某些不良心理特征,并提出了相应的解决方法及对策,以提高实验课的教学效果。希望为医学生未来科研工作的顺利进行搭建一座有效的桥梁。     

BACTERIAL EFFECTS AND ALGAL BIOREMEDIATION BY CHLORELLA ELLIPSOIDEA GERNECK OF THE BERKELEY PIT LAKE SYSTEM

Mitman, G. G. Department of Biological Sciences, Montana Tech of The University of Montana, Butte, MT 59701 The Berkeley Pit Lake System is one of the largest contaminated sites in North America and is located near the headwaters of the largest superfund site in the U.S. It is filling at a rate of about 28.7 million liters per day with metal laden, acidic (pH 2.7) water. Chlorella ellipsoidea is one of the first autochthonous species of algae from the Berkeley Pit Lake System to be tested for its bioremediative potential. An experimental matrix was designed for this experiment using a completely randomized design (CRD). The matrix was set up with tissue culture flasks having the following treatments: Na2HPO4 at 0, 25, 50, 75, 100 mg/l, inoculated vs. no- inoculated with algae (187,500 algae/ml final), and filtered (0.2Fm) vs. non filtered pit water as variables, NaNO₃ amount was fixed at 53 mg/ml. Three replicates were made of each and the experiment lasted 60 days. The results of this experiment demonstrated significant remediation of most metals. These results will be presented. In addition, filtering seemed to negatively impact the bioremediative potential of the cultures. As a result, axenic cultures of Chlorella ellipsoidea will be tested in Berkeley pit water to determine if it is bacteria or filtration that caused these results.     

有柄石韦中多糖提取工艺的优化

通过正交试验对有柄石韦中多糖提取工艺进行研究,为有柄石韦的深入开发利用提供基础材料。以多糖得率为指标,通过单因素和正交试验,对有柄石韦中多糖提取的工艺参数进行优化。超声时间、超声温度、料液比、水浴温度在多糖提取中影响因素的大小顺序为:提取时间温度料液比。有柄石韦中多糖提取最佳工艺参数组合为:超声温度40℃,提取时间60 min,料水比1∶8 g/mL,水浴时间130 min。以苯酚-硫酸法测定有柄石韦中多糖的提取率,方法可行,稳定。     

Modification of a stimulus-reinforcer interaction by blocking

With tone-light compound-stimulus training, light will gain control of responding under an appetitive schedule while tone will gain considerable control with avoidance training. The present experiment sought to determine whether this stimulus-reinforcer interaction could be modified by a “blocking” procedure. Initially, one group of rats was trained to respond for food in tone while tone-off was food free, and a second group was trained to avoid shock in light while light-out was shock free. Following attainment of a 10:1 discrimination ratio, food and avoidance schedules were signaled, for the respective groups, by a tone-light compound stimulus. An element test demonstrated that the blocking procedure overcame the stimulus-reinforcer interaction previously reported with rats in both the appetitive and avoidance groups. Contrary to previous stimulus-reinforcer interaction research, here, the tone, rather than the light, controlled responding after food training while the light, rather than the tone, controlled responding after avoidance training. These results obey predictions from associative theory. The current experiment is also the first demonstration of blocking within an instrumental avoidance procedure.     

Integration in the clonal plant <Emphasis Type="Italic">Eriophorum angustifolium</Emphasis>: an experiment with a three-member-clonal system in a patchy environment

A clonal plant in heterogeneous environments is usually expected to profit from resource exchange via a clonal network where ramets placed in contrasting environments can specialise so to acquire the most abundant resources. An experiment was designed using the three member clonal system of Eriophorum angustifolium, which consisted of one parent ramet growing in a resource poor environment and two offspring: one was limited in growth by nutrients while the other was light limited; the contrast in availability of limited resources between the offspring ramets was high, medium or none, with the system either connected or severed. The total resource availability was the same in all treatments. We proposed four possible scenarios for the system: offspring ramets will share resources via the deficient parent ramet, and the whole clone will profit from the contrasting environment (scenario 1); offspring ramets will support exclusively the parent ramet, and the whole clone will profit from a homogeneous environment (scenario 2); offspring ramets will stop the export of the limiting resource to the parent ramet, with split and connected treatments not differing (scenario 3); and offspring ramets will exhaust the carbon stored in the biomass of the parental ramet; offspring ramet will profit from connection (scenario 4). In the experiment, the limiting resources were sent to the strongest sink (scenario 2). The parent ramet growing in a deficient environment received the highest support in the treatment where both offspring ramets were growing in the same conditions (no-contrast treatment). Production of new shoots, but not biomass of whole clone, was supported in a homogenous environment. The experiment revealed that multiple stresses might prohibit free exchange of limiting resources via the clonal network and supports the idea that experimental studies on more complex clones are essential for understanding the costs and benefits of clonal growth.     

实施“三高”教学,创建“微生物学实验”课程新体系

深化微生物实验教学改革,实施“高起点、高效率、高质量”教学,从调整教学内容,改革教学方法,建立和完善考评机制入手,创建“以基础知识和基本技能为基础性内容,以创新能力培养为核心内容”的微生物学实验课程新体系,激发了学生对微生物学实验的兴趣,培养了学生独立思考、创新思维和综合动手的能力。     

EVA dosimetry in manned spacecraft

Extra Vehicular Activity (EVA) will become a large part of the astronaut's work on board the International Space Station (ISS). It is already well known that long duration space missions inside a spacecraft lead to radiation doses which are high enough to be a significant health risk to the crew. The doses received during EVA, however, have not been quantified to the same degree. This paper reviews the space radiation environment and the current dose limits to critical organs. Results of preliminary radiation dosimetry experiments on the external surface of the BION series of satellites indicate that EVA doses will vary considerably due to a number of factors such as EVA suit shielding, temporal fluctuations and spacecraft orbit and shielding. It is concluded that measurement of doses to crew members who engage in EVA should be done on board the spacecraft. An experiment is described which will lead the way to implementing this plan on the ISS. It is expected that results of this experiment will help future crew mitigate the risks of ionising radiation in space.     

从绿色荧光蛋白的发现谈如何提出新颖的科研问题

为了使研究生在获得专业知识的同时,还可以依据文献提出新的科研问题,并设计实验方案来解决提出的问题,我们以绿色荧光蛋白为案例教学,谈谈在其发现过程中是如何提出问题以及提出问题所用的思维方式。启发研究生运用求异和置换的思维方式来提出新颖的科研问题,并设计实验来回答提出的问题,从而为研究生完成学术论文奠定良好的基础。