Implementation of sustainable sanitation in existing urban areas: long-term strategies for an optimised solution.

If technologies for decentralised sanitation and reuse (DESAR) and for natural stormwater management should at least partially replace existing systems, then intensive reconstruction work becomes essential. A conversion can only be realised successively over a long period due to high construction and financial expenses and requires new strategies. This paper presents the development and practical implementation of a mathematical tool to find an optimised strategy for the realisation of alternative and more decentralised drainage and sanitation concepts in existing urban areas. The succession of construction measures (e.g. the implementation of decentralised greywater recycling) for the whole period of consideration is determined based upon a mathematical optimisation model on the condition that the favoured future state is known. The model describes the complex interdependencies of the urban water and nutrient cycle and enables the minimisation of both financial efforts and ecological impacts on the way toward the future state. The results of the implementation for a rural area in Germany show that the mathematical optimisation is an adequate instrument to support decision-making processes in finding strategies for the realisation of sustainable urban water management.

Three-dimensional ballistocardiography and respiratory motion in sustained microgravity.

BACKGROUND: We measured the three-dimensional ballistocardiogram (BCG) in a free-floating subject in sustained microgravity during spaceflight to test the usefulness of such measurements for future non-invasive monitoring of cardiac function, and to examine the effects of respiratory movement on the BCG in three axes. METHODS: Acceleration was measured using a three-axis accelerometer fastened to the lumbar region of the subject while simultaneous recordings of ECG, and respiratory motion via impedance plethysmography were also made. Data were recorded during a 146-s period of inactivity on the part of the subject during which time there was no contact with the spacecraft. RESULTS: Total body motion due to respiratory activity was consistent with that calculated from the known action of the diaphragm and conservation of momentum. The accelerations due to cardiac activity, ensemble averaged over the R-R interval, were greatest along the head-to-foot axis. Maximum amplitude of the HIJK complex of the BCG generated by ventricular ejection was greatest in the head to foot axis (approximately 70 x 10(-3) m x s(-2)), but there were also substantial accelerations along the dorsoventral axis of up to 43 10(-3) m x s(-2), that are not measured interrestrial two-dimensional studies. The amplitude of the BCG was strongly affected by lung volume, with accelerations being reduced 50 to 70% between end-inspiration and end-expiration. CONCLUSIONS: These data suggest a greatly reduced transmission of the cardiac motion to the body at end-expiration (FRC) than at higher lung volumes. The BCG might be further developed as a non-invasive means of monitoring parameters such as stroke volume in microgravity.

Beagle 2: a proposed exobiology lander for ESA's 2003 Mars Express mission.

The aim of the proposed Beagle 2 small lander for ESA's 2003 Mars Express mission is to search for organic material on and below the surface of Mars and to study the inorganic chemistry and mineralogy of the landing site. The lander will have a total mass of 60kg including entry, descent, and landing system. Experiments will be deployed on the surface using a robotic arm. It will use a mechanical mole and grinder to obtain samples from below the surface, under rocks, and inside rocks. Sample analysis by a mass spectrometer will include isotopic analysis. An optical microscope, an X-ray spectrometer and a Mossbauer spectrometer will conduct in-situ rock studies.

Microgravity environment conditions--from Spacelab to the International Space Station.

Since the early eighties Spacelab has been the primary platform for experimentation under the state of virtually weightlessness (microgravity) in spaceflight. The International Space Station (ISS), planned to be operational by end of the century, will extend the scientific opportunities of Spacelab in many respects, e.g. by offering the opportunity for long lasting and continuous microgravity investigations. Stringent design and operational requirements have been defined for the ISS to keep residual accelerations as low as possible. These guidelines are based on investigations (Langbein, Alexander, and others) of upper allowable residual accelerations for most physical phenomena involved in space experiments. To meet these requirements, severe perturbations from operating the Station (reboosts to correct the orbit, docking maneuvers, etc.) are grouped outside dedicated microgravity-experiment phases. For the microgravity-phases, stringent criteria on upper limits of residual accelerations are specified. Recent predictions for the present ISS concept indicate that additional measures have to be taken. The results of the microgravity-studies on Spacelab missions (D-1, D-2, etc.) contain a wealth of valuable information for developing optimal design principles. Passive measures must be applied first ('perturbation reduction at the source' and timelining) before considering complex active isolation concepts which should be reserved for high sensitive investigations only.

[Metachronous double carcinoma of the large intestine]. / Das metachrone Doppelkarzinom des Dickdarmes.

Seven patients developed two separate carcinomas of the colon over an average interval between the two of 8.5 years. Five of the second tumours were discovered during routine endoscopic follow-up of the first. Ten of the 14 tumours were located in the left colon. These seven cases represent an incidence of metachronous double carcinoma of the colon of 0.9% among a total of 762 patients with carcinoma of the colon seen during the same period. Two patients died of the malignancy seven and 24 months, respectively, after the operation. The others have so far remained clinically free of tumour.

Potential antineoplastics. 4th communication: N-mustard derivatives of estrone).

The nitrogen mustards 5 and 9 are synthesized as potential mammatropic antineoplastic agents from estrone via 2--4 or 6--8, respectively. 5 and 9 show a binding affinity to the cytoplasmic estrogen receptor of the rat uterus of 1--10% compared to that of estrone. Both mustard compounds are irreversibly bound to the estrogen receptor.