Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions.

Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTER's mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources.

[Cardiopulmonary Exercise Testing (CPET) in severe COPD--a multicentre comparison of two test protocols]. / Spiroergometrie bei Patienten mit chronisch obstruktiver Lungenerkrankung--multizentrischer Vergleich von zwei Belastungsprotokollen.

Cardiopulmonary exercise testing (CPET) allows a valid evaluation of cardiopulmonary function capability and the recognition of existing limitations in COPD patients. Whereas the measurement of the different parameters of CPET and the evaluation of the results are standardised, this does not apply to the protocols chosen. The aim of this study was to evaluate whether the results of two different exercise protocols were comparable in an outpatient multicentre setting. Ninety COPD patients stages II-IV according to the Gold classification were examined by means of symptom-limited exercise testing on a bicycle with two different ramp protocols (10 Watts vs. 16 Watts/min) within seven days. The results show that a higher acceleration rate of the load was associated with shorter exercise duration and higher achieved exercise capacity. Gas exchange and ventilatory parameters did not show significant differences on comparing both protocols. In pulmonary practices COPD patients of the Gold stages II-IV can be examined safely and with validity by means of CPET. The application of a ramp protocol with a stepwise increase of 16 Watts/minute can be recommended, particularly as for this regimen standardised normal values are available.

Role of a computer-generated three-dimensional laryngeal model in anatomy teaching for advanced learners.

OBJECTIVES: (1) To investigate the efficacy of a computer-generated three-dimensional laryngeal model for laryngeal anatomy teaching; (2) to explore the relationship between students' spatial ability and acquisition of anatomical knowledge; and (3) to assess participants' opinion of the computerised model. SUBJECTS AND METHODS: Forty junior doctors were randomised to undertake laryngeal anatomy study supplemented by either a three-dimensional computer model or two-dimensional images. Outcome measurements comprised a laryngeal anatomy test, the modified Vandenberg and Kuse mental rotation test, and an opinion survey. RESULTS: Mean scores ± standard deviations for the anatomy test were 15.7 ± 2.0 for the 'three dimensions' group and 15.5 ± 2.3 for the 'standard' group (p = 0.7222). Pearson's correlation between the rotation test scores and the scores for the spatial ability questions in the anatomy test was 0.4791 (p = 0.086, n = 29). Opinion survey answers revealed significant differences in respondents' perceptions of the clarity and 'user friendliness' of, and their preferences for, the three-dimensional model as regards anatomical study. CONCLUSION: The three-dimensional computer model was equivalent to standard two-dimensional images, for the purpose of laryngeal anatomy teaching. There was no association between students' spatial ability and functional anatomy learning. However, students preferred to use the three-dimensional model.

River restoration success: a question of perception.

What defines success and failure of river restoration measures is a strongly debated topic in restoration science, but standardized approaches to evaluate either are still not available. The debate is usually centered on measurable parameters, which adhere to scientific objectivity. More subjective aspects, such as landscape aesthetics or recreational value, are usually left out, although they play an important role in the perception and communication of restoration success. In this paper, we show that different perceptions of restoration success exist by analyzing data from 26 river restoration measures in Germany. We addressed both objective parameters, such as hydromorphological changes and changes in fish and benthic invertebrate assemblages, from field investigations, and subjective parameters, such as opinions and perceptions, from water managers via an online survey. With regard to the objective hydromorphological and biotic parameters, our results agree with many studies that have reported improvements in the hydromorphology following restoration; however, there is no similar agreement between results concerning changes in the benthic invertebrate and fish assemblages. The objective results do not correspond to the subjective parameters because self-evaluation of the restoration projects by water managers was overly positive. Indeed, 40% of the respondents admitted that their evaluation was based on gut feeling, and only 45% of the restoration measures were monitored or occasionally checked. This lack of objectively recorded data meant that the water managers were not able to reasonably evaluate restoration success. In contrast, some self-evaluation responses reflected a different perception of the restoration success that was based on landscape aesthetic values or on benefit for the public; others adopted a general "condemned to success" attitude. Based on our data, we argue (1) that goals should be thoughtfully formulated prior to restoration implementation and (2) that it is necessary to monitor river restoration success from different perspectives.

Purification and characterization of F420H2-dehydrogenase from Methanolobus tindarius.

The oxidation of F420H2 (reduced coenzyme F420) is a key reaction in the final step of methanogenesis. This step is catalyzed in Methanolobus tindarius by the membrane-bound F420H2-dehydrogenase which was purified 31-fold to apparent homogeneity. The apparent molecular mass of the native enzyme was 120 kDa. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed the presence of five different subunits of apparent molecular masses of 45 kDa, 40 kDa, 22 kDa, 18 kDa and 17 kDa. The purified F420H2-dehydrogenase, which was yellowish, contained 16 +/- 2 mol iron and 16 +/- 3 mol acid-labile sulfur/mol enzyme. No flavin could be detected. The oxygen-stable enzyme catalyzed the oxidation of F420H2 (apparent Km = 5.4 microM) with methylviologen and metronidazole as electron acceptors at a specific rate of 13 mumol.min-1.mg-1 (kcat = 25.5 s-1). The isoelectric point was at pH 5.0. The temperature optimum was at 37 degrees C and the pH optimum at 6.8.

Effects of self- and cross-reinnervation on the numbers of motoneurons regenerating to forearm muscles in young and adult rats.

The present study was carried out to compare the ability of motoneurons to regenerate to functionally appropriate and inappropriate muscles, following axotomy at different stages of postnatal development. Five-, 10-, 21-day-old and adult rats of both sexes were used. In one group, the right median and radial nerves were cut and reunited. In a second group, the cut nerves were cross reunited and, in a third group the nerves were merely exposed. Following survival periods of up to one year, the extent of motoneuron regeneration through the repaired nerves was determined by injecting the retrogradely transported tracers horseradish peroxidase (HRP) and Fast Blue into the flexor and extensor muscles of the right forearm. The results were expressed in terms of the difference between the number of labelled motoneurons on the experimental side of the spinal cord and the number on the control side, the latter having been labelled by injection of HRP and Fast Blue into the muscles of the left forearm. Comparisons were then made between the groups with respect to the age at which axotomy occurred, and the target of regeneration. The results showed that when axotomy was performed in 5- and 10-day-old rats, significantly fewer motoneurons were labelled, irrespective of whether or not the target was functionally appropriate, than when axotomy was performed in adulthood. The difference was most likely due to a lower survival rate of motoneurons following axotomy in neonates. No difference was found, however, between the numbers of labelled median and radial nerve motoneurons following self- versus cross-reinnervation in any age group. This suggests that, in both adult and neonatal rats, motoneurons which survive axotomy are able to regenerate equally well to functionally appropriate or inappropriate muscles.

The influence of zinc administration on the development of experimental lung metastases after an injection of tumour cells into the tail vein of rats.

Rats having received drinking water enriched with zinc (zinc acetate, 22.8 mmol/l) developed significantly more pulmonal metastases after an i.v. injection of 5 x 10(5) cultivated cells of a benzpyrene-induced sarcoma than receiving normal drinking water. Zinc ions seem to promote the emigration, implantation and outgrowth of circulating tumour cells.

Comparison of the efficiencies of true blue and diamidino yellow as retrograde tracers in the peripheral motor system.

The abilities of the fluorescent retrograde tracers true blue and diamidino yellow to label motor neurons of the rat sciatic nerve were compared quantitatively. Following injection of a mixture of the 2 tracers into the sciatic nerve, diamidino yellow was found only in double-labelled neurons, while 28% of labelled neurons contained true blue alone. The relative labelling efficiency of diamidino yellow, at only 72%, was significantly lower than that of true blue. When the tracers were injected separately a difference in the labelling efficiency was still observed but, in addition, there were significantly fewer diamidino yellow-labelled neurons than when a mixture had been injected. This suggests that the presence of true blue in the mixture had enhanced the uptake, transport or visualisation of diamidino yellow. When a mixture of true blue and diamidino yellow was applied to the cut sciatic nerve, the relative labelling efficiency of diamidino yellow (77%) was again found to be lower than that of true blue, but positive identification of diamidino yellow-labelled cells was hampered by chromatolytic changes in the cell bodies. Injection of the tracer mixture into the gastrocnemius muscle resulted in a diamidino yellow labelling efficiency (36%) significantly lower than that obtained with either nerve injection or nerve dipping. Thus, compared to true blue, diamidino yellow was either less capable of reaching the motor endplates within the muscle, or it was taken up less efficiently by axon terminals than by the axons themselves.

The arrangement of forearm motoneurons in young and adult rats and the possibility of naturally occurring motoneuron death.

The normal number and arrangement of motoneurons contributing fibres, via the median and radial nerves, to the forearm muscles of the rat were determined at different stages of postnatal development. Horseradish peroxidase was applied directly to the proximal cut ends of the nerves in 5, 10, 21 days old and adult rats. At each stage of development, the motoneuronal pool for each nerve was confined to the ipsilateral, dorsolateral area of Lamina IX. In general, median nerve motoneurons were found dorsal and medial to those of the radial nerve and were located between the rostral parts of the C6-T1 segments of the spinal cord. The radial nerve motoneuronal pool extended between the caudal end of the C4 and rostral tip of the T1 segment. There was considerable overlap between the two populations, especially along the dorsoventral axis. Counts of labelled motoneurons revealed that significantly fewer were present in adult compared to 5 days old rats (P less than 0.05 for each nerve). Approximately 50% of the motoneurons were lost from each nerve over this period. Although results from other studies suggest that part of the apparent loss may have been due to deficiencies in the HRP tracing technique, the possibility of motoneuronal death cannot be entirely excluded in this study.

Explanation for the labeling of cervical motoneurons in young rats following the introduction of horseradish peroxidase into the calf.

This study was carried out to determine whether cervical motoneurons, labeled following the introduction of horseradish peroxidase into the rat hind leg, belong to the cutaneous trunci motoneuron pool. The cutaneous trunci is a superficial muscle that extends from the axilla, over the flank, and into the thigh. Its nerve supply is derived from the brachial plexus. In experimental animals, horseradish peroxidase was either injected directly into the right gastrocnemius muscles, or applied to gelfoam and implanted over the calf muscles in the right leg of 5-, 10-, 15-day-old and adult rats. In control animals the cutaneous trunci was denervated prior to the administration of horseradish peroxidase. Labeled cervical motoneurons were present in the 5-, 10-, and 15-day-old but not the adult experimental groups and were located within the predetermined confines of the cutaneous trunci motoneuron pool. No labeling of cervical motoneurons was observed in any of the control groups in which the cutaneous trunci muscle was denervated. The most likely explanation for the labeling of cervical motoneurons in young rats was the local diffusion of horseradish peroxidase from the calf to the thigh, where it entered the cutaneous trunci muscle and was taken up by some of its motoneurons. The absence of such labeling in adult rats was probably due to the presence of connective tissue barriers to diffusion and to the greater distance between the site of horseradish peroxidase application and the cutaneous trunci muscle, which prevented the tracer from reaching the cutaneous trunci muscle and labeling its motoneurons.

[Effect of the oral administration of zinc on metastasis after intravenous application of benzpyrene-induced rat sarcoma cells]. / Zur Wirkung oral applizierten Zinks auf die Metastasenbildung nach intravenöser Applikation von Zellen eines benzpyreninduzierten Rattensarkoms.

In experimental investigations it was shown that rats having received drinking water enriched by zinc acetate (22.8 mmol/l) developed significantly more pulmonary metastases after an intravenous infection of cells of a benzpyrene-induced rat sarcoma than rats receiving normal drinking water. This increase is caused by an increase of the number of rats developed metastases as well as the number of metastases of the individual rat.

Influence of operations for stress incontinence and/or genital descensus on sexual life.

A variety of operations for stress incontinence or genital descensus are performed in gynecological department. The purpose of this study was to find out whether these operations influenced the patients' sexual life. In a prospective study of 55 women, all sexually active prior to the operation, various characteristics were evaluated by interview and gynaecological examination, immediately before and 6 months after the operation. We had adviced early resumption of sexual intercourse. Postoperatively, 13 of 55 (24%) patients experienced improvement in their sexual life, 37 of 55 (67%) no change, and 5 of 55 (9%) experienced a deterioration. Improvement often resulted from cessation of urinary incontinence. Deterioration was in all 5 cases due to dyspareunia and all 5 patients underwent a posterior colporrhaphy as part of the operation. We conclude that provided the patients are well-informed the prognosis for sexual life after these operations is good. However, colpoperineoplasty in combination with anterior colporrhaphy might cause dyspareunia in some patients.

Risk factors and sib correlation in physiological neonatal jaundice.

The effect of a number of explanatory variables on the degree of physiological jaundice in mature infants was evaluated by multiple regression analysis. The sampling was designed so that comparisons could be made between siblings. We found an effect of gestational age, gender, infant nutrition, ABO incompatibility and induction of labour. Taking these factors into account we still found a highly significant correlation between the peak bilirubin levels of siblings. Whether this correlation is genetically or environmentally determined is not clear.

On the diffusion of horseradish peroxidase into muscles and the "spurious" labeling of motoneurons.

There is some evidence to suggest that the fascial sheaths of muscles are important in preventing the labeling of motoneurons that occurs, apparently, as a result of the diffusion of horseradish peroxidase (HRP) into the muscles. To test this possibility, Gelfoam soaked in HRP was implanted over flexor and extensor muscles in the proximal forelimb of the rat. When the fascial sheaths were damaged, labeled neurons were found in the motoneuronal pools of the exposed muscles; if intact, virtually no labeling of motoneurons was observed. These results suggest that, if intramuscular injections are to be used as a method for identifying motoneuronal pools, care should be taken when exposing the muscle to be injected, to ensure that surrounding muscles and their fascial sheaths are not damaged.

Labeling of motoneurons supplying the cutaneous maximus muscle in the rat, following injection of the triceps brachii muscle with horseradish peroxidase.

Injection of the triceps brachii muscle of the rat with horseradish peroxidase (HRP) led to labeling of motoneurons in the dorsolateral and ventral aspects of the ventral grey horn of the brachial spinal cord. Ventral, labeled neurons were absent, however, in rats in which the motor branches of the radial nerve to triceps were exposed to HRP. Cutting the radial nerve, prior to the injection of the triceps, did not diminish this ventral labeling, whereas cutting both the radial nerve and the nerves to the cutaneous maximus muscle before injection completely eliminated it. Leakage or diffusion of HRP from the triceps and its subsequent uptake by damaged fibers of the cutaneous maximus muscle was the most likely cause of the labeling of the ventrally located motoneurons.