Space hardware for concrete sample production on ISS "MASON concrete mixer".

Advances in space flight technology will enable the construction of Moon or even Mars bases in the not-too-distant future. Thus, materials will be needed that are suitable for building in microgravity environments. One idea is to use concrete, the most used construction material on Earth, for these challenging tasks. The hardening and the properties of concrete under the boundary conditions prevailing on Earth are well understood, but there is only limited research on concrete produced in microgravity. Hence, a research project called MASON was established, which aims to mix and harden concrete on the ISS and to investigate the properties of the specimens made in microgravity extensively. Since a defined geometry of the specimens would be favorable for these investigations, a special hardware was developed, called the MASON Concrete Mixer (MCM), which allows the production of concrete specimens fulfilling the requirements on the geometry as well as the safety requirements. Subsequently, the development, design, tests, and qualification of the MCM as well as its usage are presented.

Approaches to assess the biodiversity of bacteria in natural habitats.

Any attempt to characterize a bacterial community and their functional genes coding for enzymes of the nitrogen cycle is faced with its extreme biodiversity. Novel techniques, based on PCR amplification of target genes in DNA from environmental samples, have been developed for characterizing both cultured and as yet uncultured bacteria in the last few years. Computer-based assignment tools have now been developed utilizing terminal restriction fragments obtained from digestions with multiple restriction enzymes. Such programs allow the gross characterization of bacterial life in any complex bacterial community with confidence.

Prenatal diagnosis of severe structural congenital malformations in Europe.

OBJECTIVES: To assess at a population-based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators. METHODS: In the period 1995-1999, data were obtained from 17 European population-based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis. RESULTS: The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25-88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36-88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P < 0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30-40% of the pregnancies with a prenatal diagnosis were terminated. CONCLUSION: European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the "culture" in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies.

[Prevention of congenital malformations by means of folic acid - insurmountable problems due to the German penal code and German drug legislation when preparing a preconceptional model in Saxony-Anhalt]. / Die Fehlbildungsprävention durch Folsäure - unlösbare Probleme mit Paragraph 20 SGB V und der Arzneimittelgesetzgebung bei der Vorbereitung eines perikonzeptionellen Modells in Sachsen-Anhalt1.

For the last 20 years the prophylactic effect of the vitamin folic acid against the occurrence of neural tube defects has been known but in Germany this fact has not been realized by the public. The recommendations by medical institutions fail, among other reasons, because a folic acid prescription by gynaecologists comes too late in the course of events, i.e., women go to the gynaecologist when pregnancy has already set in and it is too late for preventive measures. An effective folic acid prophylaxis must take place before the onset of pregnancy. Data from the regional surveillance of congenital anomalies of the German Federal State of Saxony-Anhalt and interviews with women in maternity, as well as gynaecologists, indicate that there is a substantial knowledge deficit concerning folic acid prophylaxis. In 1998, therefore, a working group was set up in Saxony-Anhalt. It comprises representatives from interested institutions and has the goal of rectifying the knowledge deficit of women of childbearing age by way of a broad-based campaign while making use of the results of regional congenital anomalies monitoring. A pharmaceutical company was enlisted for cost-free distribution of its folic acid product. Legal problems with the prescription drug laws, the law against unfair competitive practices, the advertising of medicaments law and the SGB V (social code) made it impossible to procure multivitamins containing folic acid free of charge for women wanting a child. A highly differentiated legislation has hitherto prevented an elementary improvement in prevention.

Down's syndrome: the effects of prenatal diagnosis and demographic factors in a region of the eastern part of Germany.

The epidemiological analysis of trisomy 21 presented for the new federal German state of Saxony-Anhalt describes trends and changes in the frequency of Down's syndrome and prevalences of the pregnancy outcomes including acceptance of prenatal diagnostic measures in the period from 1980 and with separate analysis for the period since reunification in 1990. The average prevalence in the entire period is 1.0 per 1000 births. In 1997, a prevalence of 1.7 per 1000 births was already observed. After 1990, there is an increase in the prevalence of conceptions with trisomy 21 whereas the prevalence of live births with Down's syndrome remained the same. The reasons for this are an increase in the age of the mothers and a broad acceptance of prenatal diagnostics. Ethical questions, that might for example reveal societal changes in the attitude to children with Down's syndrome have not been considered in the analysis, since this would require sociological investigations which cannot be carried out by the malformations register.

[Reduction in malformation-related early mortality--a possibility for modifying perinatal mortality]. / Senkung der fehlbildungsbedingten Frühsterblichkeit--eine Möglichkeit zur Beeinflussung der perinatalen Mortalität.

From 1980 to 1996 1.8% of all births died as a result of malformations during the first week of life. This rate has been declining significantly after 1992. Congenital malformations of the heart have increased significantly because of improved diagnostic methods. From 1980 to 1996 0.67/1000 of all children died of vitium cordis during the first week of life. From 1992 to 1996 this group of malformations increased the perinatal mortality rate by 0.4/1000. There is a decreased mortality rate of neural tube defects by 0.25/1000 1980 to 1986 and by 0.08/1000 1992 to 1996. Trisomy 21: the early mortality rate decreased from 0.07/1000 to 0.03/1000. The number of non-deceased children with Down's syndrome remains constant, even though 40 per cent of all cases with trisomy 21 were prenatal. 3 per cent of all malformed newborn died during the first week of life as a result of their congenital malformations. The possibility of primary prevention of malformations with folic acid has not been sufficiently utilised.

[Prevention of folic acid-induced malformations--recommendations and reality]. / Fehlbildungsprotektion durch Folsäure--Empfehlungen und Realität.

Periconceptional intake of folic acid is one of only few possibilities of preventing congenital malformations. We report on the update situation of applying folic acid and the effects on the prevalence of neural tube defects and oral clefts. The analysis is based on data of the malformation registry in Saxony-Anhalt. A common public campaign on the benefit of folic acid protection is presented.

Cloning and characterization of the nuclear AC115 gene of Chlamydomonas reinhardtii.

The nuclear ac115 mutant of Chlamydomonas reinhardtii is specifically blocked in the synthesis of the chloroplast encoded D2 protein of the photosystem II reaction center at a point after translation initiation. Here, we report the identification of the AC115 gene through complementation rescue of the ac115 mutant strain, using an indexed cosmid library of Chlamydomonas genomic DNA. AC115 is a small, novel, intronless nuclear gene which encodes a protein of 113 amino acids. The amino terminal end of the Ac115 protein is rich in basic amino acids and has features which resemble a chloroplast transit sequence. A hydrophobic stretch of amino acids at the protein's carboxyl terminus is sufficiently large to be a membrane spanning or a protein/protein interaction domain. Various models are discussed to account for the mechanism by which Ac115p works in D2 synthesis. The ac115 mutant allele was sequenced and determined to be an A-to-T transversion at the first position of the fourth codon of the coding sequence. This mutation changes an AAG codon to a TAG nonsense codon and results in a null phenotype.

[Detection of abnormalities in Magdeburg according to the Mainz model]. / Fehlbildungserfassung nach dem Mainzer Modell in Magdeburg.

Between 09/01/92 and 08/31/95 the Mainz model to register birth defects had been tested in the city of Magdeburg at the same time when the regional register instituted in 1980 was continued. The aim of this hospital-based model for the thorough registry of malformations in neonates is to examine all newborns born in hospitals using clinical and sonographical methods by experienced physicians according to a standardized scheme. Additional medical and social data were recorded. Data on live-and stillborn as well as spontaneous abortions older than the 16th gestational week and induced abortions following prenatal diagnosis were included. During the survey 5255 neonates were examined. The calculated percentage of major birth defects (by definition) was 7.8% and therefore higher than reported before. The experience with the Mainz model in the city of Magdeburg demonstrates, that this model is basically applicable to other centres. It is possible to obtain valid data on malformation frequencies in a defined population. Special attention has to be paid to certain conditions in the composition of hospital populations.

[Incidence of neural tube defects in the Magdeburg administrative district]. / Die Häufigkeit von Neuralrohrdefekten im Regierungsbezirk Magdeburg.

The Magdeburg Register of birth defects includes information on the incidence rate of neural tube defects (NTD) in the city of Magdeburg since 1980, and in the Regierungsbezirk (administrational district) since 1987. The average prevalence of NTD was 16.4 per 10,000 births in the city of Magdeburg, and 12 per 10,000 births in the surrounding counties. Besides of this significant difference between the city and counties, there are conspicuous variations from one year to the next. In 1987 the prevalence of NTD was about 27 per 10,000 births in the city of Magdeburg whereas the observed prevalence in the countryside was about 19 per 10,000 births. Different eating habits and/or increased teratogenic influences in the city may be considered as causes. In 1997 there was also a high rate of incidence of NTD in the city of Magdeburg--16.4 per 10,000 births. The incidence rate of NTD in the counties (about 10 per 10,000) births) is again lower than in the city. Because of these incidence rates, we may assume that the examined population is insufficiently protected by folic acid in the preconceptional stage.

Translation of the chloroplast psbA mRNA requires the nuclear-encoded poly(A)-binding protein, RB47.

A set of nuclear mutants of C. reinhardtii were identified that specifically lack translation of the chloroplast-encoded psbA mRNA, which encodes the photosystem II reaction center polypeptide D1. Two of these mutants are deficient in the 47-kD member (RB47) of the psbA RNA-binding complex, which has previously been identified both genetically and biochemically as a putative translational activator of the chloroplast psbA mRNA. RB47 is a member of the poly(A)-binding protein family, and binds with high affinity and specificity to the 5' untranslated region of the psbA mRNA. The results presented here confirm RB47's role as a message-specific translational activator in the chloroplast, and bring together genetic and biochemical data to form a cohesive model for light- activated translational regulation in the chloroplast.

[From "reporting" to "surveillance": documentation of abnormalities within the scope of perinatal data collection--a sensitive instrument for monitoring new technologies?]. / Vom "Reporting" zum "Surveillance": Die Fehlbildungsdokumentation im Rahmen der Perinatalerhebung--ein sensibles Instrumentarium zum Monitoring neuer Technologien?

Analysis of the Hamburg perinatal quality assurance programme shows a dramatic increase in congenital abnormalities of the bones, joints and muscles from 45.29 per 10,000 live births in 1990 to 106.32 in 1994. Comparisons with other perinatal quality assurance programme data reveal almost the same trend. In fact, there is no real increase in these specific congenital abnormalities, but there is an effect, which can be explained by the introduction of ultrasound hip screening in infancy signalling overdiagnostics due to the new technology. This example demonstrates that the perinatal quality assurance programme is a suitable instrument for registering congenital abnormalities and monitoring new technologies and interventions. These results support the proposal by the association of the leading state health officers (AGLMB) to use the already well-established quality assurance programmes which are analysed on state level for a systematic nation-wide documentation and "surveillance" of congenital abnormalities. In addition, it becomes clear that surveillance, understood as a further development of health reporting, offers an opportunity to effect both an assessment and a better orientation in respect of health policies.

Three-dimensional 31P magnetic resonance spectroscopic imaging of regional high-energy phosphate metabolism in injured rat heart.

The purpose of this study was to measure the spatially varying 31P MR signals in global and regional ischemic injury in the isolated, perfused rat heart. Chronic myocardial infarcts were induced by occluding the left anterior descending coronary artery eight weeks before the MR examination. The effects of acute global low-flow ischemia were observed by reducing the perfusate flow. Chemical shift imaging (CSI) with three spatial dimensions was used to obtain 31P spectra in 54-microl voxels. Multislice 1H imaging with magnetization transfer contrast enhancement provided anatomical information. In normal hearts (n = 8), a homogeneous distribution of high-energy phosphate metabolites (HEP) was found. In chronic myocardial infarction (n = 6), scar tissue contained negligible amounts of HEP, but their distribution in residual myocardium was uniform. The size of the infarcted area could be measured from the metabolic images; the correlation of infarct sizes determined by histology and 31P MR CSI was excellent (P < 0.006). In global low-flow ischemia (n = 8), changes of HEP showed substantial regional heterogeneity. Three-dimensional 31P MR CSI should yield new insights into the regionally distinct metabolic consequences of various forms of myocardial injury.

[Incidence of ectromelia deformities in the Magdeburg region]. / Häufigkeit von Reduktionsdeformitäten der Extremitäten (R.D.) in der Region Magdeburg.

Since there is no nationwide system and documentation of congenital malformations in Germany, local health authorities were not able to respond to the question of an increase in limb reduction defects occurring on the coast of Northern Germany. Previously, such an increase had been reported by the media in England in 1994. For limb reduction defects, the feasibility and efficiency of the so-called "Magdeburg-model" for monitoring congenital malformations is demonstrated. This model provides data on reduction defects for analysing regional (Magdeburg versus Magdeburg county) and temporal trends, and for classifying reduction defects. The data are based on a population of 214.901 births (lifebirths and stillbirths) and on the analysis of 64 cases with limb reduction defects over a 15-year period. In 1992-1994 in Magdeburg and Magdeburg county no increase of limb reduction defects and other indicator malformations were found.