BIOLAB, EPU and EMCS for cell culture experiments on the ISS

Two ESA facilities are under development for biological research on the International Space Station: BIOLAB as part of the European "Columbus" Laboratory and the European Modular Cultivation System (EMCS), foreseen for accommodation in the US Lab "Destiny". Both facilities have an incubator (18-40 degrees C) and use standard Experiment Containers, mounted on two centrifuge rotors providing either microgravity or variable g-levels from 0.001 x g to 2.0 x g. Standard interface plates supply each container with power and data lines, with gas (controlled CO2, O2 and water vapour concentration; trace gas removal), and--for EMCS only--with water. The degree of automation is higher in BIOLAB: it contains a robotic Handling Mechanism for automatic sampling and handling of liquids, which can be stored at cool or cold temperatures or injected for automatic on-board analysis into a microscope or a spectrophotometer. For analyses on the running centrifuge, small automatic microscopes can be installed in the Experiment Containers. Several designs for supporting cell culture experiments have been studied for BIOLAB and EMCS. BIOLAB has in addition a Bio-Glovebox, which can be sterilised and where new cell cultures may be prepared under 1 x g conditions from deep-frozen samples in the Experiment Preparation Unit (EPU): the cryo-protectant will be removed by automatic washing cycles. Both facilities, EMCS and BIOLAB (with EPU), have also provisions for telescience operations through video, data and command lines, either operated by the crew or by the experimenter on ground.     

Development of a plant growth support system for experiments on the ISS

The European Modular Cultivation System (EMCS) is one of a wide range of laboratory modules under construction by ESA that will be placed on the International Space Station (ISS). In the present study the development and construction of an important component in the EMCS, the Plant Cultivation Container (PCC), is described. The PCC as a "flower pot" will automatically provide the plants with water and liquid nutrients as needed. The PCC is located inside the plant growth unit, the Experiment Container (EC), on the EMCS and interfaces with the EMCS. The essential parts of the PCC are a Peltier element, a micro valve, a monitoring RH sensor with an integrated platinum RTD temperature sensor, a RH sensor that detects air leaving the PCC and controls the peristaltic pump, a DC-DC board that provides correct current to the Peltier element, and a switch/connector board. The PCC is presently being tested out at ESTEC/ESA.     

Medical care for Russian cosmonauts on board the ISS

Established with the personal participation of O.G. Gazenko, the Russian system of medical care for cosmonauts has been largely preserved to this day. The system was fully functional on board the orbital complex Mir and, with appropriate modifications, has been adopted as the core of the medical care for Russian members of ISS crews. In 2000–2008, 22 cosmonauts were members of 17 ISS missions lasting from 140 to 216 days. The main functions of the medical care system were to control health, physical, and mental performance, and to support space research. Readaptation to normal gravity was, in most cases, similar to what has been typical on the return from Russian orbital stations; some deviations are accounted for by the use of in-flight countermeasures. The paper presents some aspects of the theoretical work of Academician Gazenko in the field of medical care in space flights. It outlines the principles of ISS medical management. The integrated medical support system combines medical equipment and items available in the Russian and U.S. segments; the integrated medical group consists of flight surgeons, medical experts, and biomedical engineers of international partners and coordinates the planning and implementation of medical operations. In addition, challenges of health care in the phase of ISS operation are defined.     

Plant growth regulators-assisted phytoextraction

Plant growth regulators (PRG)-assisted phytoremediation is a technique that could enhance the yield of heavy metal accumulation in plant tissues. So far, a small number of experiments have helped identify three groups of plant hormones that may be useful for this purpose: auxins, cytokinins, and gibberellins. Studies have shown that these hormones positively affect the degree of accumulation of metallic impurities and improve the growth and stress resistance of plants. This review summarizes the present knowledge about PGRs’ impact on phytoextraction yield.     

Fast parallel tandem mass spectral library searching using GPU hardware acceleration

Mass spectrometry-based proteomics is a maturing discipline of biologic research that is experiencing substantial growth. Instrumentation has steadily improved over time with the advent of faster and more sensitive instruments collecting ever larger data files. Consequently, the computational process of matching a peptide fragmentation pattern to its sequence, traditionally accomplished by sequence database searching and more recently also by spectral library searching, has become a bottleneck in many mass spectrometry experiments. In both of these methods, the main rate-limiting step is the comparison of an acquired spectrum with all potential matches from a spectral library or sequence database. This is a highly parallelizable process because the core computational element can be represented as a simple but arithmetically intense multiplication of two vectors. In this paper, we present a proof of concept project taking advantage of the massively parallel computing available on graphics processing units (GPUs) to distribute and accelerate the process of spectral assignment using spectral library searching. This program, which we have named FastPaSS (for Fast Parallelized Spectral Searching), is implemented in CUDA (Compute Unified Device Architecture) from NVIDIA, which allows direct access to the processors in an NVIDIA GPU. Our efforts demonstrate the feasibility of GPU computing for spectral assignment, through implementation of the validated spectral searching algorithm SpectraST in the CUDA environment.     

Plant growth and climate change

‘Climate change’ is an all-embracing subject: increasingcarbon dioxide concentration in the atmosphere, due to the insatiableappetite of our burgeoning Homo sapiens (or perhaps better H.carbonovorum) populations for energy from fossil carbon reserves,is the main driver. The consequent global warming may lead tovery complex     

Plant olfaction: using analytical chemistry to elucidate mechanisms of plant growth and interaction

Background and Scope

Growing evidence suggests that volatile organic compounds (VOCs) play important roles in plant-plant, plant-microbe and plant-environment interactions. Demonstrating such mechanisms requires the use of innovative analytical techniques to monitor VOCs in and above soils. In this issue, Waters et al. provide experimental evidence that stolons of the woodland strawberry, Fragaria vesca, forage for nutrient-rich soil patches by a chemotropic mechanism.

Conclusions

These experimental results not only help clarify the means by which this clonal plant locates nutrients in a heterogeneous environment, but also demonstrate the power of using the tools of modern analytical chemistry to elucidate plant-plant and plant-environment interactions.

     

Plant growth regulators and the orchid cut-flower industry

Research involving plant growth regulators (PGRs) and orchids in areas of orchid growth and development are reviewed. For all areas covered in the review — seed germination and seedling growth, lateral shoot production, root production, flower initiation and development, postharvest physiology, and photosynthate partitioning — it was concluded that further studies would assist in clarifying potential uses for PGRs in the orchid cut-flower industry. It is suggested that extra PGR research on orchids is justified at the present time because of favourable prospects facing the orchid cut-flower industry.     

Plant growth modelling without integrating mechanisms

The integration of root and shoot activity for resource acquisition and allocation is a central problem both in experimental physiology and in mathematical growth modelling. A key feature in all proposed solutions is the mechanism by which roots and shoot communicate their resource status, their needs or their demands. In experimental studies, chemical messengers (hormones or nutrients) have been central. In mathematical models, partitioning or productivity functions of one form or another have been incorporated to fill a similar role. In this paper, the central hypothesis is that growth and resource allocation can be based solely on local, internal, non-structural resource concentrations and local kinetic rules, without the need for additional mechanisms to integrate activities at the organis-mal level. The specific objective was to develop a formal model using the classical two-compartment, two-resource framework which did not include direct intercompartmental coordinating or communicating mechanisms or resource partitioning functions. The formalization effort was successful based on two criteria. First, the ‘plants’ grow at steady and balanced rates when ‘growth conditions’ are constant; and second, challenged with experimental manipulations such as pruning or limitations in resource acquisition, their growth responses mimic those of real plants. Analysis of the results indicates that the complex integrated growth patterns of the modelled plants are emergent properties – having no direct or indirect mechanistic basis – of the simple system. They imply that similar ‘mechanism-less’ integration is possible in real plants as an emergent property of strictly local, cellular-level activities.     

Plant growth promotion and Penicillium citrinum

Background

Lamivudine is an oral nucleoside analogue widely used for the treatment of chronic hepatitis B. The main limitation of lamivudine use is the selection of resistant mutations that increases with time of utilization. Hepatitis B virus (HBV) isolates have been classified into eight genotypes (A to H) with distinct geographical distributions. HBV genotypes may also influence pathogenic properties and therapeutic features. Here, we analyzed the HBV genotype distribution and the nature and frequency of lamivudine resistant mutations among 36 patients submitted to lamivudine treatment for 12 to 84 months.

Results

Half of the patients were homosexual men. Only 4/36 (11%) patients were HBV DNA negative. As expected for a Brazilian group, genotypes A (24/32 positive individuals, 75%), D (3/32, 9.3%) and F (1/32, 3%) were present. One sample was from genotype C, which is a genotype rarely found in Brazil. Three samples were from genotype G, which had not been previously detected in Brazil. Lamivudine resistance mutations were identified in 20/32 (62%) HBV DNA positive samples. Mean HBV loads of patients with and without lamivudine resistance mutations were not very different (2.7 × 10⁷ and 6.9 × 10⁷ copies/mL, respectively). Fifteen patients showed the L180M/M204V lamivudine resistant double mutation. The triple mutant rt173V/180M/204V, which acts as a vaccine escape mutant, was found in two individuals. The three isolates of genotype G were entirely sequenced. All three showed the double mutation L180M/M204V and displayed a large genetic divergence when compared with other full-length genotype G isolates.

Conclusion

A high (55%) proportion of patients submitted to long term lamivudine therapy displayed resistant mutations, with elevated viral load. The potential of transmission of such HBV mutants should be monitored. The identification of genotypes C and G, rarely detected in South America, seems to indicate a genotype distribution different to that observed in non treated patients. Disparities in routes of transmission (genotype G seems to be linked to homosexual behavior) and in pathogenic properties (genotype C is very aggressive) among HBV genotypes may explain the presence of rare genotypes in the present work.     

Plant growth regulation with triazoles of the dioxanyl type

The plant growth retarding activities of several dioxanylalkyl and dioxanylalkenyl triazoles were determined in seedlings of barley, rice, and oilseed rape. Out of these groups some substances proved to be among the most efficient growth retardants known. The compound 1-(4-trifluormethyl)-2-(1,2,4-triazolyl-(1))-3-(5-methyl-1,3-dioxan-5-yl)-propen-3-ol was investigated more closely. Shoot growth is reduced more intensively than root growth by this compound. At lower dosages root growth may even be stimulated. The action of this retardant can be antagonized by gibberellin A₃ and byent-kaurenoic acid. It is suggested that its main biochemical action is to block the reactions that lead froment-kaurene toent-kaurenoic acid in the course of gibberellin biosynthesis.     

Plant DNA extraction using silica

Described here is a method that uses silicon dioxide (silica) to extract whole genomic plant DNA of high molecular weight. The protocol is presented in a microcentrifuge format, and yields were approximately 2–4 μg per 200 mg of plant leaf tissue. The method involves fewer steps than many previous extraction protocols and, as shown here for 4 taxonomically distant angiosperms, produces DNA suitable for digestion with restriction endonucleases. The use of commercial kits is not required; the silica costs are comparatively inexpensive (<$0.03 per tube); and CTAB, rather than the more expensive guanidine thiocyanate salt, is used.     

Plant growth regulation with triazoles of the dioxanyl type

The plant growth retarding activities of several dioxanylalkyl and dioxanylalkenyl triazoles were determined in seedlings of barley, rice, and oilseed rape. Out of these groups some substances proved to be among the most efficient growth retardants known. The compound 1-(4-trifluormethyl)-2-(1,2,4-triazolyl-(1))-3-(5-methyl-1,3-dioxan-5-yl)-propen-3-ol was investigated more closely. Shoot growth is reduced more intensively than root growth by this compound. At lower dosages root growth may even be stimulated. The action of this retardant can be antagonized by gibberellin A₃ and byent-kaurenoic acid. It is suggested that its main biochemical action is to block the reactions that lead froment-kaurene toent-kaurenoic acid in the course of gibberellin biosynthesis.     

EPM - The European Facility for human physiology research on ISS

The European Physiology Modules (EPM) Facility is one of the four major Space Station facilities being developed within the framework of ESA's Microgravity Facilities for Columbus (MFC) programme. In order to allow a wide spectrum of physiological studies in weightlessness conditions, the facility provides the infrastructure to accommodate a variable set of scientific equipment. The initial EPM configuration supports experiments in the fields of neuroscience, bone & muscle research, cardiovascular research and metabolism. The International Space Life Science Working Group (ISLSWG) has recommended co-locating EPM with the 2 NASA Human Research Facility racks.