Amino acids as possible alternative nitrogen source for growth of Euglena gracilis Z in life support systems

In recent times Euglena gracilis Z was employed as primary producer in closed environmental life-support system (CELSS), e.g. in space research. The photosynthetic unicellular flagellate is not capable of utilizing nitrate, nitrite, and urea as nitrogen source. Therefore, ammonium is supplied as an N-source in the lab (provided as diammonium-dihydrogenphosphate, (NH4)2HPO4) to E. gracilis cultures. While nitrate exerts low toxicity to organisms, ammonium is harmful for many aquatic organisms especially, at high pH-values, which causes the ionic NH4+ (low toxicity) to be partially transformed into the highly toxic ammonia, NH3. In earlier reports, Euglena gracilis was described to grow with various amino acids as sole N-source. Our aim was to investigate alternatives for (NH4)2HPO4 as N-source with lower toxicity for organisms co-cultivated with Euglena in a CELSS. The growth kinetics of Euglena gracilis cultures was determined in the presence of different amino acids (glycine, glutamine, glutamic acid, leucine, and threonine). In addition, uptake of those amino acids by the cells was measured. Cell growth in the presence of glycine and glutamine was quite comparable to the growth in (NH4)2HPO4 containing cultures while a delay in growth was observed in the presence of leucine and threonine. Unlike, aforementioned amino acids glutamate consumption was very poor. Cell density and glutamate concentration were almost unaltered throughout the experiment and the culture reached the stationary phase within 8 days. The data are compared with earlier studies in which utilization of amino acids in Euglena gracilis was investigated. All tested amino acids (glutamate with limitations) were found to have the potential of being an alternative N-source for Euglena gracilis. Hence, these amino acids can be used as a non-toxic surrogate for (NH4)2HPO4.

Soilless cultivation of soybean for Bioregenerative Life-Support Systems: a literature review and the experience of the MELiSSA Project - Food characterisation Phase I

Higher plants play a key role in Bioregenerative Life-Support Systems (BLSS) for long-term missions in space, by regenerating air through photosynthetic CO2 absorption and O2 emission, recovering water through transpiration and recycling waste products through mineral nutrition. In addition, plants could provide fresh food to integrate into the crew diet and help to preserve astronauts' wellbeing. The ESA programme Micro-Ecological Life-Support System Alternative (MELiSSA) aims to conceive an artificial bioregenerative ecosystem for resources regeneration, based on both microorganisms and higher plants. Soybean [Glycine max (L.) Merr.] is one of the four candidate species studied for soilless (hydroponic) cultivation in MELiSSA, because of the high nutritional value of the seeds. Within the MELiSSA programme - Food characterisation Phase I, the aim of the research carried out on soybean at the University of Naples was to select the most suitable European cultivars for cultivation in BLSS. In this context, a concise review on the state-of-the-art of soybean cultivation in space-oriented experiments and a summary of research activity for the preliminary theoretical selection and subsequent agronomical evaluation of four cultivars will be presented in this paper.

[Use of the ion-exchange substrate to optimize mineral nutrition of plants within a bio-engineering life support system with a high level of closure]

Purpose of the work was to test manageability of nutrient solutions containing mineralized human exometabolites by using an ion-exchange substrate (IES) for cultivating wheat in a bio-engineering life support system with a high level of closure. Object of the investigation was wheat Triticum aestivum L. (Lysovsky cv. l. 232). Crops were raised on clayite in a growth chamber of a hydroponic conveyor system under continuous light. Correction of nutrient solution was to lift the limits of crop supply with minerals. The experimental crop grew in nutrient solution with immersed IES "BIONA-312"; nutrient solution for the control crop was corrected by adding mineral salts. Solution correction did not have a noteworthy effect on the yield, CO2-gas exchange or mineral composition of wheat plants. IES makes simple the technology of plant cultivation on solutions enriched with human exometabolites.

[Promising technique of mineral supply organization for plants in the condition of microgravity]

The proposed system of automated nutrient solution preparation for plant cultivation in microgravity consists of an ion-exchange fabric artificial soil (AS) as a root-inhabited medium, a pack with slow release fertilizer as the main source of nitrogen, phosphorus and potassium and a cartridge with a granular mineral-rich ionite as a source of calcium, magnesium, sulphur and iron. Experiments proved that fabric AS BIONA-V3 is capable to stabilize pH of the substrate solution within the range of 6.0 to 6.6 favorable to the majority of vegetable cultures. The experimental data attested suitability of this technique of water forcing through mineral-containing packs to automate nutrient solution preparation for crops cultivated in space greenhouses, and to minimize the stock of fabric AS onboard the space vehicle.

[Use of ion-exchange substrates for optimizing the mineral supply to plants within life support systems]

The main goal of the work is to validate ion-exchange substrates as optimizers of plant mineral supply within bio-engineering systems of life support with a high level of closure. Test objects were spring Lisovsky wheat-232 and leaf cabbage Sensuji-kyomizuna. Crops were cultivated on artificial soil (AS) in environmentally controlled plant growth chambers. Prior to seeding, AS was enriched simultaneously with wheat straw and ion-exchange substrate BIONA-312 to the extent of 2, 10 or 20% of AS dry mass. Incorporation of the ion-exchange substrate in the amount of 10% increased crop productivity and eliminated the negative effect of wheat straw. Ion-exchange substrate in amount of 20% did not yield a noticeable gain in productivity as compared with the previous test.

The role of synthetic biology for in situ resource utilization (ISRU)

A persistent presence in space can either be supported from Earth or generate the required resources for human survival from material already present in space, so called "in situ material." Likely, many of these resources such as water or oxygen can best be liberated from in situ material by conventional physical and chemical processes. However, there is one critical resource required for human life that can only be produced in quantity by biological processes: high-protein food. Here, recent data concerning the materials available on the Moon and common asteroid types is reviewed with regard to the necessary materials to support the production of food from material in situ to those environments. These materials and their suitability as feedstock for the biological production of food are reviewed in a broad and general way such that terminology that is often a barrier to understanding such material by interdisciplinary readers is avoided. The waste products available as in situ materials for feasibility studies on the International Space Station are also briefly discussed. The conclusion is that food production in space environments from in situ material proven to exist there is quite feasible.

Ambient habitat noise and vibration at the Georgia Aquarium

Underwater and in-air noise evaluations were completed in performance pool systems at Georgia Aquarium under normal operating conditions and with performance sound tracks playing. Ambient sound pressure levels at in-pool locations, with corresponding vibration measures from life support system (LSS) pumps, were measured in operating configurations, from shut down to full operation. Results indicate noise levels in the low frequency ranges below 100 Hz were the highest produced by the LSS relative to species hearing thresholds. The LSS had an acoustic impact of about 10 dB at frequencies up to 700 Hz, with a 20 dB re 1 μPa impact above 1000 Hz.

[Microbial fuel cells as an alternative power supply]

Purpose of the work was designing and prototyping of microbial fuel cells (MFC) and comparative evaluation of the electrogenic activity of wastewater autochthonous microorganisms as well as bacterial monocultures. Objects were model electrogenic strain Shewanella oneidensis MR-1, and an Ochrobactrum sp. strain isolated from the active anode biofilm of MFC composed as an electricity generating system. The study employed the methods typically used for aerobic and anaerobic strains, current measurement, identification of new electrogenic strains in microbial association of wastewater sludge and species definition by rRNA 16-S. As a result, two MFCs prototypes were tried out. Besides, it was shown that electrogenic activity of S. oneidensis MR-1 and Ochrobactrum sp. monocultures is similar but differs from that of the microbial association of the anode biofilm.

[Methods of extending the resource of fiber ionite artificial soils in space greenhouses]

The vegetable cultivation technology developed in view of long-term autonomous missions is based on root nutrition provided by fiber artificial soils (AS) containing ion-exchange resins. Useful life of ASs is limited by two factors which are nutrients depletion in ion-exchanger and clogging of the AS threshold space by roots remnants. Purpose of the investigation is to try out hydrolysis and ensuing microbial decomposition of roots remnants as a way to extend the resource of used fiber ionite AS. This principle of doing away with the roots remnants recovers almost completely the maximal water-absorbing capacity of AS BIONA-V3 so that it can be used again for crops cultivation.

[Optimization of the mineral nutrition of plants constituting the phototrophic component of closed biological life support systems]

Applicability of a new substrate for crops cultivation in bioregenerative LSSs with a high degree of mass-exchange closure was tested. Optimization of leaf cabbage nutrition by supplementing the basic substrate fabricated of plant and animal residues with ion-exchange resins proved to have a success.

[Evaluation of potentiality of combined SHF- and glow discharge in intensification of carbon dioxide and hydrogen processing within life support system]

The article reports an experimental carbon dioxide hydration process in combined SHF- and glow discharge, and describes a design of SHF plasmatrones for CO2 processing at air pressure and in an integrated unit. Maximal transformation of 80% CO2 per a run was reached with the total input power of no more than 0.9 kW. Thermal zero lag of plasma forming, essentially instant and timely engagement and disengagement of thermal action on CO2-H2 mixture renders SHF-energy applicable to intensification of next generation life support technologies, processing of these gases within atmosphere regeneration system specifically.

Good life good death according to Christiaan Barnard

Christiaan Barnard (1922-2002), pioneering heart transplant surgeon, introduced his ideas on euthanasia in a well-written and researched book, Good Life Good Death. A Doctor's Case for Euthanasia and Suicide, published in 1980. His courage in analyzing this topic in a forthright and clear manner is worth reviewing today. In essence, Barnard supported and practiced passive euthanasia (the ending of life by indirect methods, such as stopping of life support) and discussed, but never practiced, active euthanasia (the ending of life by direct means). Barnard believed that "the primary goal of medicine was to alleviate suffering-not merely to prolong life-he argued that advances in modern medical technology demanded that we evaluate our view of death and the handling of terminal illness." Some in the surgical community took issue with Barnard when he publicized his personal views on euthanasia. We discuss Barnard's beliefs and attempt to clarify some misunderstandings regarding this particular controversial area of medicine.

[Comparative evaluation of productivity of several green cultures as potential higher plant components of bio-regenerative systems of life support]

Purpose of the investigation was to select, analyze and evaluate green plant species known for assisting resistance to diseases and improving physiological functions in humans, and to test allelopathic compatibility of selected species with basic systems for life support. Nutrient substrates were freshly made soil-like substrate (SLS) and clayite. Green cultures were 6 spinach species, 2 lettuces, 2 leaf cabbage species and ruccola. The investigations showed that plant productivity was either equal to or better on freshly made SLS than on clayite; however, the greens accumulated large quantities of nitrate nitrogen. The highest productivity distinguished leaf cabbage; the best antiradical properties was demonstrated by lettuces and the worst, by some spinach species. None of the species displayed a negative allelopathic effect on productivity of the reddish test culture.

[Combined effect of zeatin and hydrogen peroxide on growth of rape and tomato germs as applied to the conditions of biological life support systems]

Cytokine-regulated growth of germs' roots and hypocotyls was investigated on a background of modeled oxidative outbreak caused by the stress from exogenous hydrogen peroxide. Germs of rape (1-d old) and tomato (56-d old) in Petri dishes with solutions containing substances under study were subjected to 24-48 hour incubation in the dark. Exogenous zeatin inhibited growth; in different tests treatment with H2O2 brought about both acceleration and inhibition of root and hypocotyl growth. The combined use of two substances deformed concentration curves. Hydrogen peroxide concentration of 100 microM without cytokines inhibited growth of tomato root significantly, whereas application of 0.003-0.01 and 0.9 microM of zeatin intensified root growth. The series of zeatin concentration-effect curves obtained for rape roots and hypocotyls with gradually increasing H2O2 concentration included the inhibition curve (w/o H2O2), curve with predominant growth stimulation and reliable maximum (1 microM of H2O2), intermediate shape curves (0.3 and 3.3-10 microM). Hence, biological life support systems should be designed with consideration for variability of effects of physiologically active substances under conditions of stress.

NAVA ventilation

Neurally adjusted ventilatory assist (NAVA) is a form of partial ventilatory support wherein the machine applies positive pressure to the airway opening throughout each inspiration. In contrast to all other modes of ventilation, which adopt conventional pneumatic signals (flow, volume, and airway pressure) to drive and control the ventilator operation, NAVA utilizes the electrical activity of the diaphragm, which is the best available signal to estimate the respiratory drive and to trigger on and cycle off the delivery of the mechanical assistance and regulate its amount and intra-breath profile. With NAVA, therefore, the patient retains full control of the breathing pattern. Following the first description of NAVA ten years ago, various studies have been performed on this mode of ventilation, either in animal models, healthy subjects, or in adult and pediatric critically ill patients. These investigations indicate that this novel mode is efficient in unloading the respiratory muscles and maintaining adequate gas exchange while improving the patient-ventilator interaction. This review article aims to summarize the results of the studies published to date on this topic.

[Polyphase character of the dependence of Brassica napus germ root and hypocotyl growth on zeatin and thidiazuron concentrations with view of applicability to biological life support systems]

Physiologically active substances are considered as a potential component of plant cultivation technologies for biological life support systems. In spacelight, plant reactions to growth-regulating agents may be changed by the specific stress factors such as microgravity, radiation, and trace admixtures in cabin air. Complex character of the concentration dependence of PAS efficiency and consequent variability generate a need to optimize plant growth regulating technologies in order to stabilize the wanted effect. Pattern of the concentration dependence of zeatin and tidiazurone effects on roots and hypocotyls growth was analyzed in rape germs. 24-hour Brassica napus germs grown in the dark in thermostat at 24 degrees C were transferred to Petri dishes with solutions of cytokinins under study for continued incubation under the same conditions for the next 24 hours. Roots and hypocotyls were measured. Zeatin concentration curve for roots was multiphase and, in addition to the general trend towards greater inhibition with increase of phyto-hormone concentration and had clearly defined minimum and maximum. The dependence of root growth inhibition on tidiazurone concentration also was not monotonic and had a distinct similarity with the zeatin curve. Gradual increase of tidiazurone concentration used in combination with zeatin brought about a predictable gradual twist of the zeatin curve; however, in most of the instances no additive cytokinin effect was observed. A supposition can be made that PAS interaction with the phytohormone regulation system may be a factor in variability of activity of these substances.

[Percutaneous extracorporeal life support in acute severe hemodynamic collapses: single centre experience in 100 consecutive patients]

BACKGROUND

Extracorporeal life support (ECLS) is a circulatory assistance device that is increasingly used in adults undergoing cardiopulmonary arrest (CPA) or hemodynamic collapse when conventional therapies fail.

OBJECTIVES

To assess the feasibility and outcomes of 100 consecutive arteriovenous percutaneous ECLS procedures at the Grenoble University Hospital between January 2002 and September 2007.

METHODS

Monocentric descriptive registry with one-year prospective follow-up.

RESULTS

An ECLS device was successfully used in 93% of patients. Its indication was cardiogenic shock in 50% of the cases, CPA in 38% of the cases and unsuccessful weaning of cardiopulmonary bypass (CPB) after cardiothoracic surgery in 12% of the cases. Direct complications of ECLS were observed in 56% of patients, the most frequent being hemorrhage at the intravenous puncture site requiring red blood cell transfusions (26%), and lower limb ischemia (19%). Weaning from ECLS was achieved in 33 patients (44% cardiogenic shocks, 13% CPAs, 50% CPB weaning failures) and 20 patients were discharged from the hospital (26% cardiogenic shocks, 10.5% CPAs and 25% CPB weaning failures). All are still living without any serious sequelae (mean follow-up period of 16.8 months).

CONCLUSION

The use of ECLS in CPA patients, especially with cardiogenic shock, is feasible with satisfactory survival rates, given the extreme severity of their initial state.

[Mathematical model of carbon oxide in pressurized chamber during long-term human habitation]

A new approach to quantitative assessment of CO measurements in atmosphere of continuously operating pressurized module GVK-250 has been proposed. It was established that implementation of scheduled operations in the module transform nonstationary CO laws to low-ergodic. The total amount of atmospheric CO decreases substantially as soon as gas emission reaches a low-ergodic condition. Results of the investigation have been brought up to computational procedures and can be instrumental in the course of long-term run of pressurized modules and experimental works.

Morphological, physiological and behavioural evaluation of a 'Mice in Space' housing system

Environmental conditions likely affect physiology and behaviour of mice used for life sciences research on Earth or in Space. Here, we analysed the effects of cage confinement on the weightbearing musculoskeletal system, behaviour and stress of wild-type mice (C57BL/6JRj, 30 g b.wt., total n = 24) housed for 25 days in a prototypical ground-based and fully automated life support habitat device called "Mice in Space" (MIS). Compared with control housing (individually ventilated cages) the MIS mice revealed no significant changes in soleus muscle size and myofiber distribution (type I vs. II) and quality of bone (3-D microarchitecture and mineralisation of calvaria, spine and femur) determined by confocal and micro-computed tomography. Corticosterone metabolism measured non-invasively (faeces) monitored elevated adrenocortical activity at only start of the MIS cage confinement (day 1). Behavioural tests (i.e., grip strength, rotarod, L/D box, elevated plus-maze, open field, aggressiveness) performed subsequently revealed only minor changes in motor performance (MIS vs. controls). The MIS habitat will not, on its own, produce major effects that could confound interpretation of data induced by microgravity exposure during spaceflight. Our results may be even more helpful in developing multidisciplinary protocols with adequate scenarios addressing molecular to systems levels using mice of various genetic phenotypes in many laboratories.

[Possible ways to include human exometabolites in the turnover of biological life support system]

Purpose of the investigation was to study feasibility to include solid and liquid human discharges in the turnover of bioregenerative life support systems for physical/chemical and biological treatment. Human exometabolites were mineralized by way of wet process in hydrogen peroxide in alternating electromagnetic field. The resultant solutions were used to water plants cultivated on a soil-like substrate or haydite. Given that urea as a source of nitrogen for BLSS is undesirable, in one of the experiments mineralization was followed by enzymatic urea decomposition with soybean flour urease. The experiments showed no difference in the productivity of plants cultivated on a standard mineral medium and with the use of mineralized exometabolites.

[The model of nighttime carbon oxide variation in atmosphere of a habitable pressurized module]

A mathematical model was found to describe variations in atmospheric carbon oxide during night sleep of chambered test subjects. The analytical expressions make possible calculation of CO concentration in artificial atmosphere. The model was constructed from the factual laboratory test data and can be used in designing of life support systems.

[Pediatric cases in preclinical emergency medicine: critical aspects in the range of missions covered by ground ambulance and air rescue services]

BACKGROUND

The aim of this study was to demonstrate differences in structure and severity of pediatric emergencies treated by aeromedical (air rescue) or ground ambulances services. Conclusions for the training of emergency physicians are discussed.

PATIENTS AND METHODS

In a 3-year study period, a total of 9,274 pediatric emergencies covered by the ADAC air rescue service are compared to 4,344 pediatric patients of ground ambulance services in Saarland.

RESULTS

In aeromedical services pediatric emergencies are more frequent (12.9% vs. 6.4%), trauma predominates (59.9% vs. 35.6%) and severe injuries or diseases occur more frequently (30.5% vs. 15.0%). In both groups pediatric emergency cases are concentrated into very few diagnostic groups: more than one third of the cases involving pre-school children is due to convulsions. Respiratory diseases and intoxication are the next most frequent causes and are more common in ground ambulance patients. Head trauma is the most common diagnosis in cases of pediatric trauma, followed by musculoskeletal and thoracoabdominal trauma. All types of severe trauma are more frequent in pediatric patients of the aeromedical services.

CONCLUSIONS

Training of emergency physicians should include pediatric life support and specific information about frequent pediatric emergency situations. For emergency physicians in aeromedical services, an intensive training in pediatric trauma life support is also necessary.

Optimizing edible fungal growth and biodegradation of inedible crop residues using various cropping methods

Long-term manned space flights to Mars require the development of an advanced life support (ALS) ecosystem including efficient food crop production, processing and recycling waste products thereof. Using edible white rot fungi (EWRF) to achieve effective biomass transformation in ALS requires optimal and rapid biodegradative activity on lignocellulosic wastes. We investigated the mycelial growth of Lentinula edodes and Pleurotus ostreatus on processed residues of various crops under various cropping patterns. In single cropping, mycelial growth and fruiting in all strains were significantly repressed on sweet potato and basil. However, growth of the strains was improved when sweet potato and basil residues were paired with rice or wheat straw. Oyster mushroom (Pleurotus) strains were better than shiitake (L. edodes) strains under single, paired, and mixed cropping patterns. Mixed cropping further eliminated the inherent inhibitory effect of sweet potato, basil, or lettuce on fungal growth. Co-cropping fungal species had a synergistic effect on rate of fungal growth, substrate colonization, and fruiting. Use of efficient cropping methods may enhance fungal growth, fruiting, biodegradation of crop residues, and efficiency of biomass recycling.

[Investigation of intermetalloid hydrogen sorption-desorption in physical-chemical life support system]

A hydrogen accumulating alloy was tested for safe sorption and storage of electrolyzed hydrogen within life support system. The alloy of choice was intermetalloid LaNi5 absorbing and desorbing hydrogen at approximately room temperature and pressure A of 20 atm. Sorption was evaluated at hydrogen pressure A of 0.1; 0.2 and 0.3 atm. The rate of desorption was controlled at 2.0 l/min to maintain the standard carbon dioxide and hydrogen feed into the processor. Results of the investigation lead to the main conclusion that the hydrogen accumulating alloy can be an integral component of a new generation of life support systems.

[Iodine-containing urine preservative]

One of the formidable problems of exploration missions is creation of autonomous water-closed life support systems. Sources of water for regeneration could be various water-containing human wastes including urine, the most chemically contaminated liquid. Prior to physical/chemical regeneration, urine first must be decontaminated in order to put a stop to microbiological processes that form harmful and volatile compounds contaminating condensate and drastically reducing the service life of afterpurifucation filters. Bactericide, sporocide and fungicide effectiveness of two iodine-containing preservatives was tested. One of them contains a water solution of iodine--potassium iodide and sulphuric acid. The other has medical poly-vinyl pyrrolidone to neutralize iodine toxicity. The broad antimicrobial spectrum of two iodine-containing urine preservatives and adaptability of microorganisms to a new environment are key arguments for serial use of these and other preservatives in regenerative physical/chemical systems of water supply in space exploration missions.

From the deep sea to the stars: human life support through minimal communities

Support of human life during long-distance exploratory space travel or in the creation of human habitats in extreme environments can be accomplished using the action of microbial consortia inhabiting interconnected bioreactors, designed for the purpose of reconversion of solid, liquid and gaseous wastes produced by the human crew or by one of the compartments of the bioregenerative loop, into nutritional biomass, oxygen and potable water. The microorganisms responsible for bioregenerative life support are part of Earth's own geomicrobial reconversion cycle. Depending on the resources and conditions available, minimal life support systems can be assembled using appropriately selected microorganisms that possess metabolic routes for each specific purpose in the transformation cycle. Under control of an engineered system, a reliable life-support system can hence be provided for.

Failure of vascular autoregulation in the upper limb with increased +Gz acceleration

Forearm pain occurring during high +Gz exposure has been linked with vascular distension from elevated transmural pressure of hydrostatic origin and is exacerbated by positive pressure breathing (PBG). We postulated that at high vascular transmural pressure vascular autoregulation might be overcome and be associated with worsened pain. Six volunteers were studied at +4, +5, +6, and +7 Gz on a human centrifuge. Forearm vascular resistance (FVR) was assessed by Doppler ultrasound resistive index (RI), and superficial forearm venous pressure (FVP) was measured via an indwelling catheter. Pain rating was assessed by numerical scale. The left arm was located at heart level (control position), or on the throttle (test position). Runs were completed with and without positive pressure breathing for G protection (PBG); subjects wore full coverage anti-G trousers and chest counter-pressure. In the test position, pain increased with increasing acceleration (P < 0.0001), and was more severe with PBG at +5 Gz and +7 Gz (P < 0.05). FVP rose substantially more in the test than control position (238 +/- 17 mmHg vs. 61 +/- 8 mmHg at +7 Gz, P < 0.0001) but the presence or absence of PBG had no effect on the FVP increase during acceleration in either position. In the test position, RI fell with increasing acceleration above +5 Gz (P < 0.0001), and the fall was greater with PBG (P < 0.05). Forearm pain was thus associated with a decrease in FVR and an increase in vascular transmural pressure. PBG exacerbated forearm pain and prompted a greater fall in RI, but had no effect on FVP response. These findings support FVR but not forearm venous distension in the aetiology of +Gz arm pain.

Managing intensive supports. The attitudes of the health care workers of five Italian Hospitals to institution of CPR and admission to the ICU

AIM

The aim of the paper was to examine the attitudes of the health care workers (HCW) of five Italian Hospitals towards intensive supports, in the hypothesis that a large involvement could help to solve the problems of a more adequate management of vital supports.

METHODS

DESIGN

Hospital HCWs' attitudes towards cardiopulmonary resuscitation (CPR) and ICU admission were investigated using a self-administered questionnaire.

SETTING

five Italian Hospitals.

PARTICIPANTS

all the doctors (MD) and nurses (RN), except those working in obstetrics and in paediatrics.

INTERVENTION

a questionnaire was offered to all eligible participants (4903 HCW) and 2466 analysable files (50.3%) were obtained.

RESULTS

In spite of a great variation in responses among health care givers, the majority of answers is almost in line with current professional and bioethical documents, at both international and national level. This, also when the proposed solution is not clearly recognised by the Italian laws. The statistically significant differences depend on profession (RN/MD), on working area and experiential working characteristics. A strict minority of workers would trust their colleagues in case of hypothetical personal critical illness.

CONCLUSIONS

Our data confirm both the importance of communication among HCW, in order to reach the best decision for every patient, and the great need of continuous educational programs which could compensate for lack of experience and help to create/maintain a strong bioethical and patient-oriented attitude.

The key changes in pediatric and neonatal cardiopulmonary resuscitation

The American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) were changed in 2005. There were some key changes in the recommendations for pediatric basic and advanced life support, and neonatal resuscitation. The key changes included: emphasis on effective compressions (push hard, push fast, allow full chest recoil and minimize interruptions in compressions), a single compression-ventilation ratio (30:2) CPR for all groups of ages (except neonate), confirmation of effective ventilations, medication given and defibrillator charged without interruption of CPR, not recommended to routine tracheal suction the vigorous meconium-stained baby in newborn resuscitation, etc. We illustrate the major key changes and hope everyone is well trained to perform high quality CPR.

Exposure of Arabidopsis thaliana to hypobaric environments: implications for low-pressure bioregenerative life support systems for human exploration missions and terraforming on Mars

Understanding how hypobaria can affect net photosynthetic (P (net)) and net evapotranspiration rates of plants is important for the Mars Exploration Program because low-pressured environments may be used to reduce the equivalent system mass of near-term plant biology experiments on landers or future bioregenerative advanced life support systems. Furthermore, introductions of plants to the surface of a partially terraformed Mars will be constrained by the limits of sustainable growth and reproduction of plants to hypobaric conditions. To explore the effects of hypobaria on plant physiology, a low-pressure growth chamber (LPGC) was constructed that maintained hypobaric environments capable of supporting short-term plant physiological studies. Experiments were conducted on Arabidopsis thaliana maintained in the LPGC with total atmospheric pressures set at 101 (Earth sea-level control), 75, 50, 25 or 10 kPa. Plants were grown in a separate incubator at 101 kPa for 6 weeks, transferred to the LPGC, and acclimated to low-pressure atmospheres for either 1 or 16 h. After 1 or 16 h of acclimation, CO(2) levels were allowed to drawdown from 0.1 kPa to CO(2) compensation points to assess P (net) rates under different hypobaric conditions. Results showed that P (net) increased as the pressures decreased from 101 to 10 kPa when CO(2) partial pressure (pp) values were below 0.04 kPa (i.e., when ppCO2 was considered limiting). In contrast, when ppCO(2) was in the nonlimiting range from 0.10 to 0.07 kPa, the P (net) rates were insensitive to decreasing pressures. Thus, if CO(2 )concentrations can be kept elevated in hypobaric plant growth modules or on the surface of a partially terraformed Mars, P (net) rates may be relatively unaffected by hypobaria. Results support the conclusions that (i) hypobaric plant growth modules might be operated around 10 kPa without undue inhibition of photosynthesis and (ii) terraforming efforts on Mars might require a surface pressure of at least 10 kPa (100 mb) for normal growth of deployed plant species.

Air contaminants in a submarine equipped with air independent propulsion

The Swedish Navy has operated submarines equipped with air independent propulsion for two decades. This type of submarine can stay submerged for periods far longer than other non-nuclear submarines are capable of. The air quality during longer periods of submersion has so far not been thoroughly investigated. This study presents results for a number of air quality parameters obtained during more than one week of continuous submerged operation. The measured parameters are pressure, temperature, relative humidity, oxygen, carbon dioxide, hydrogen, formaldehyde and other volatile organic compounds, ozone, nitrogen dioxide, particulate matter and microbiological contaminants. The measurements of airborne particles demonstrate that air pollutants typically occur at a low baseline level due to high air exchange rates and efficient air-cleaning devices. However, short-lived peaks with comparatively high concentrations occur, several of the sources for these have been identified. The concentrations of the pollutants measured in this study do not indicate a build-up of hazardous compounds during eight days of submersion. It is reasonable to assume that a substantial build-up of the investigated contaminants is not likely if the submersion period is prolonged several times, which is the case for modern submarines equipped with air independent propulsion.

[Parametric control of the yield characteristics and species composition dynamics of algal poly-culture]

There are several experimental models of biological life support systems (BLSS) designed to incorporate a chlorella pool. These BLSS can be optimized if populated by algal associations that could take up more functions within the closed cycling system than a single alga species. Introduction of a Spirulina and Chlamydomonas poly-culture with differing in gas exchange and biochemical composition resulted in a tighter closure of linkages within the system. The factors determining the size of a species population in intensive continuous poly-cultures are, first and foremost, pH and suspension flow rate. Experimental testing of this supposition brought us to the conclusion that parametric control of alga productivity and species composition dynamics makes it possible to create a steady intensive poly-culture as part of the LSS for humans. Flow rate and pH can be the parameters for control of the Spirulina and Chlamydomonas populations during continuous cultivation of this poly-culture.

Teleoperation support for early human planetary missions

A renewed interest in human exploration is flourishing among all the major spacefaring nations. In fact, in the complex scene of planned future space activities, the development of a Moon base and the human exploration of Mars might have the potential to renew the enthusiasm in expanding the human presence beyond the boundaries of Earth. Various initiatives have been undertaken to define scenarios and identify the required infrastructures and related technology innovations. The typical proposed approach follows a multistep strategy, starting with a series of precursor robotic missions to acquire further knowledge of the planet and to select the best potential landing sites, and evolving toward more demanding missions for the development of a surface infrastructure necessary to sustain human presence. The technologies involved in such a demanding enterprise range from typical space technologies, like transportation and propulsion, automation and robotics, rendezvous and docking, entry/reentry, aero-braking, navigation, and deep space communications, to human-specific issues like physiology, psychology, behavioral aspects, and nutritional science for long-duration exposure, that go beyond the traditional boundaries of space activities. Among the required elements to support planetary exploration, both for the precursor robotic missions and to sustain human exploration, rovers and trucks play a key role. A robust level of autonomy will need to be secured to perform preplanned operations, particularly for the surface infrastructure development, and a teleoperated support, either from Earth or from a local base, will enhance the in situ field exploration capability.

Efficiency of liquid cooling garments: prediction and manikin measurement

INTRODUCTION

We studied the efficiency of liquid cooling garments (LCG) and their relationship to the insulation of outer clothing, perfusate inlet temperatures, and environmental conditions by both theoretical analysis and thermal manikin (TM) testing.

METHODS

An equation to estimate LCG cooling efficiency was developed on the basis of energy balance. Cooling efficiency is a function of the thermal resistance between the TM skin and perfusate in the LCG, the thermal resistance between the environment and the perfusate, and TM skin, ambient, and perfusate temperatures. Three ensembles, a cooling vest (CV) only, CV plus a battle dress uniform (CVB), and CVB plus a battle dress overgarment (CVO), were tested on a sweating TM in dry and wet conditions. The TM surface temperature was maintained at 33 degrees C and the environment was 30 degrees C and 50% RH. The LCG heat removal from the TM was calculated using the power inputs to the TM with and without perfusate flow.

RESULTS

The cooling efficiency was increased from approximately 0.45 for CV to approximately 0.70 for CVO in dry experiments and from approximately 0.53 for CV to 0.78 for CVO in wet experiments.

CONCLUSION

With additional outer clothing layers, higher thermal resistances increased the rate of heat removal from the TM surface, and decreased heat gain from the ambient environment, thus increasing efficiency. The perfusate inlet temperature had minimal influence on the efficiency. The equations developed can predict cooling efficiency and heat removal rates under a wider range of environmental conditions.

Advance directives, best interests and clinical judgement: shifting sands at the end of life

End-of-life issues for clinical practice present complex ethical, moral and legal dilemmas that have been heightened by advances in medical technology enabling a dying patient to be kept alive for longer than ever before. Respect for patient autonomy and dignity are fundamental ethical components that engage in end-of-life decision-making. A mentally competent individual has the absolute right to refuse medical treatment for any reason and a valid advance directive for the refusal of treatment is binding in the event that the person loses capacity. In the incompetent patient, the withdrawal of life-sustaining treatment is based on the 'best interests' test, developed on a model that takes into account the welfare considerations of the person concerned. It is questioned whether the test should be more subjectively based, and accord greater weight to the wishes that might have been in the mind of the incompetent person approaching the end of life. The Mental Capacity Act 2005 (expected to come into force in 2007) provides a statutory framework for the law relating to advance directives, capacity and best interests. This paper examines contemporary issues surrounding end-of-life decision-making against the backdrop of the existing and proposed legal framework.

Open-system chamber for measurements of gas exchanges at plant level

Gas exchanges of whole canopy can be studied by covering entire plants with a chamber and using portable infrared gas analyzers (IRGAs) to measure CO2 and H2O exchanged with the air blown through the chamber enclosure. The control of temperature rise inside the chamber, which should be kept low, and the accurate measurement of the air flow are two crucial aspects for realistic and precise estimation of photosynthesis and transpiration. An automated open-system plant chamber (clear flexible balloon enclosure) for small plants was developed to ameliorate such a technique. The temperature rise is here predicted by heat balance analysis inside the chamber. The analysis shows that when as much as 500 W m2 of solar radiation is converted to sensible heat, a flow rate of 0.98 mol s(-1) (approximately = 20 L s(-1)) of air blown into a cylinder-shaped enclosure (0.8 m high, 0.5 m wide) is adequate to limit temperature increase to 2 K. An improved calibration for the measurement of the chamber airflow was obtained by combining the use of a Pitot tube anemometer with the classical CO2 injection approach. The concentration increase due to the injection of CO2 at a known rate into the chamber was predicted by the air flow calculated from the "Pitot" air velocity. The turbulent regime of air assured that a single-point Pitot measurement was enough for a good estimation (slope = 0.99; R2 = 0.999) of the actual air flow. The open-system chamber was tested on potted sunflower (Helianthus annuus, L.) and maize (Zea mays, L.) plants under variable solar radiation, temperature, and air humidity during the daytime. As expected, similar rates of maximal leaf-area based photosynthesis (about 40 micromol m(-2) s(-1)) were observed in the two species confirming the reliability of our system. The consistency of data also resulted from the typical relationships observed between photosynthetic rate and light.

Culture of Spirulina platensis in human urine for biomass production and O(2) evolution

Attempts were made to culture Spirulina platensis in human urine directly to achieve biomass production and O(2) evolution, for potential application to nutrient regeneration and air revitalization in life support system. The culture results showed that Spirulina platensis grows successfully in diluted human urine, and yields maximal biomass at urine dilution ratios of 140 approximately 240. Accumulation of lipid and decreasing of protein occurred due to N deficiency. O(2) release rate of Spirulina platensis in diluted human urine was higher than that in Zarrouk medium.

Microbial ecology of the closed artificial ecosystem MELiSSA (Micro-Ecological Life Support System Alternative): reinventing and compartmentalizing the Earth's food and oxygen regeneration system for long-haul space exploration missions

MELiSSA is a bioregenerative life support system designed by the European Space Agency (ESA) for the complete recycling of gas, liquid and solid wastes during long distance space exploration. The system uses the combined activity of different living organisms: microbial cultures in bioreactors, a plant compartment and a human crew. In this minireview, the development of a short-cut ecological system for the biotransformation of organic waste is discussed from a microorganism's perspective. The artificial ecological model--still in full development--that is inspired by Earth's own geomicrobiological ecosystem serves as an ideal study object on microbial ecology and will become an indispensable travel companion in manned space exploration.

Suitability of different photosynthetic organisms for an extraterrestrial biological life support system

In the present era of intensive space and planetary research, efficient life support systems (LSSs) are needed to maintain suitable living conditions when humans move into space, i.e. away from the Earth's atmosphere. Thus far, such suitable conditions on various space flights and on the space stations (Mir and the International Space Station) have been maintained solely via physical and chemical means (transport of O2, H2O and food from the Earth, cleaning and recycling of air and water). However, for long-duration missions to distant destinations, such as exploratory missions to Mars, biological life support systems (BLSSs) may be needed to convert local CO2 and H2O to O2, and to food. As on earth, this conversion process would need to be based on photosynthesis. Use of higher plants and microalgae as BLSS organisms has been intensively studied. Here we review the growth requirements of these two types of photosynthetic organisms, with particular attention to their suitability for use in harsh Martian conditions, i.e. low temperatures, low atmospheric pressure, high CO2 concentration, high UV radiation and dryness.

The SOS-LUX-TOXICITY-Test on the International Space Station

For the safety of astronauts and to ensure the stability and integrity of the genome of microorganisms and plants used in bioregenerative life support systems, it is important to improve our knowledge of the combined action of (space) radiation and microgravity. The SOS-LUX-TOXICITY test, as part of the TRIPLE-LUX project (accepted for flight at Biolab in Columbus on the International Space Station, (ISS)), will provide an estimation of the health risk resulting from exposure of astronauts to the radiation environment of space in microgravity. The project will: (i) increase our knowledge of biological/health threatening action of space radiation and enzymatic DNA repair; (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation; (iii) provide specified biosensors for spacecraft milieu examination; and (iv) provide experimental data on stability and integrity of bacterial DNA in spacecrafts. In the bacterial biosensor "SOS-LUX-Test" developed at DLR (patent), bacteria are transformed with the pBR322-derived plasmid pPLS-1 or the similar, advanced plasmid SWITCH, both carrying the promoterless lux operon of Photobacterium leiognathi as the reporter element controlled by a DNA damage-dependent SOS promoter as sensor element. A short description of the space experiment is given, and the current status of adaptation of the SOS-LUX-Test to the ISS, i.e. first results of sterilization, biocompatibility and functional tests performed with the already available hardware and bread board model of the automated space hardware under development, is described here.

Caenorhabditis elegans survives atmospheric breakup of STS-107, space shuttle Columbia

The nematode Caenorhabditis elegans, a popular organism for biological studies, is being developed as a model system for space biology. The chemically defined liquid medium, C. elegans Maintenance Medium (CeMM), allows axenic cultivation and automation of experiments that are critical for spaceflight research. To validate CeMM for use during spaceflight, we grew animals using CeMM and standard laboratory conditions onboard STS-107, space shuttle Columbia. Tragically, the Columbia was destroyed while reentering the Earth's atmosphere. During the massive recovery effort, hardware that contained our experiment was found. Live animals were observed in four of the five recovered canisters, which had survived on both types of media. These data demonstrate that CeMM is capable of supporting C. elegans during spaceflight. They also demonstrate that animals can survive a relatively unprotected reentry into the Earth's atmosphere, which has implications with regard to the packaging of living material during space flight, planetary protection, and the interplanetary transfer of life.

Microgravity effects on thylakoid, single leaf, and whole canopy photosynthesis of dwarf wheat

The concept of using higher plants to maintain a sustainable life support system for humans during long-duration space missions is dependent upon photosynthesis. The effects of extended exposure to microgravity on the development and functioning of photosynthesis at the leaf and stand levels were examined onboard the International Space Station (ISS). The PESTO (Photosynthesis Experiment Systems Testing and Operations) experiment was the first long-term replicated test to obtain direct measurements of canopy photosynthesis from space under well-controlled conditions. The PESTO experiment consisted of a series of 21-24 day growth cycles of Triticum aestivum L. cv. USU Apogee onboard ISS. Single leaf measurements showed no differences in photosynthetic activity at the moderate (up to 600 micromol m(-2) s(-1)) light levels, but reductions in whole chain electron transport, PSII, and PSI activities were measured under saturating light (>2,000 micromol m(-2) s(-1)) and CO(2) (4000 micromol mol(-1)) conditions in the microgravity-grown plants. Canopy level photosynthetic rates of plants developing in microgravity at approximately 280 micromol m(-2) s(-1) were not different from ground controls. The wheat canopy had apparently adapted to the microgravity environment since the CO(2) compensation (121 vs. 118 micromol mol(-1)) and PPF compensation (85 vs. 81 micromol m(-2) s(-1)) of the flight and ground treatments were similar. The reduction in whole chain electron transport (13%), PSII (13%), and PSI (16%) activities observed under saturating light conditions suggests that microgravity-induced responses at the canopy level may occur at higher PPF intensity.

Liver support systems: promise and reality

Effective liver support is needed for a variety of indications. A large number of both biological (containing hepatocytes) and non-biological extracorporeal liver support systems have been described in the literature over the last 50 years. Despite this, there is a paucity of good quality randomized control data examining the effectiveness of these therapies in human liver failure. In this review article, we examine the available data, with particular emphasis on the current front runners, the MARS and HepatAssist systems. Other problems associated with the development of these liver support systems are also discussed. Although promising in animal studies, we conclude that the use of these technologies is not supported currently by a sufficient evidence base to recommend them for routine clinical use and that a lack of understanding about the critical functions required of a liver support system is retarding a more rational approach to the design of these systems.

Discussing living wills. A qualitative study of a German sample of neurologists and ALS patients

Patients suffering from amyotrophic lateral sclerosis (ALS) eventually lose their ability to communicate their treatment preferences in later stages of the disease. A living will enables ALS patients to specify their choices concerning life-sustaining treatment in advance. Our premise was that completion of a living will should be preceded by a discussion between patient and physician. We conducted a qualitative study of a sample of 15 neurologists and 15 ALS patients from two neurology centers in Germany. Our aim was to explore how discussions about living wills are undertaken. Data analysis followed grounded theory techniques. Our findings showed that both the patients and the physicians considered living wills to be closely connected to forthcoming death. Physicians waited for respiratory failure to occur before they informed ALS patients about living wills, an information strategy that we called the "wait-and-see-policy". The patients completed their living will when they had accepted the hopelessness of their disease. They mostly used living will forms and did not see the necessity to set down disease-specific preferences. They intended to wait for symptoms to emerge before they made the decision about whether or not to accept life-sustaining treatment. The patients as well as the physicians pursued a wait-and-see policy towards end-of-life care, thus weakening the purpose of living wills. Our results point to the necessity and importance of an open and honest patient-physician communication which is a prerequisite for the discussion of living wills.