Reversible and irreversible impacts of greenhouse gas emissions in multi-century projections with the NCAR global coupled carbon cycle-climate model

The legacy of historical and the long-term impacts of 21st century greenhouse gas emissions on climate, ocean acidification, and carbon-climate feedbacks are investigated with a coupled carbon cycle-climate model. Emission commitment scenarios with zero emissions after year 2100 and 21st century emissions of 1,800, 900, and 0 gigatons of carbon are run up to year 2500. The reversibility and irreversibility of impacts is quantified by comparing anthropogenically-forced regional changes with internal, unforced climate variability. We show that the influence of historical emissions and of non-CO2 agents is largely reversible on the regional scale. Forced changes in surface temperature and precipitation become smaller than internal variability for most land and ocean grid cells in the absence of future carbon emissions. In contrast, continued carbon emissions over the 21st century cause irreversible climate change on centennial to millennial timescales in most regions and impacts related to ocean acidification and sea level rise continue to aggravate for centuries even if emissions are stopped in year 2100. Undersaturation of the Arctic surface ocean with respect to aragonite, a mineral form of calcium carbonate secreted by marine organisms, is imminent and remains widespread. The volume of supersaturated water providing habitat to calcifying organisms is reduced from preindustrial 40 to 25% in 2100 and to 10% in 2300 for the high emission case. We conclude that emission trading schemes, related to the Kyoto Process, should not permit trading between emissions of relatively short-lived agents and CO2 given the irreversible impacts of anthropogenic carbon emission

Detection of amplified DNA sequences by reverse chromosome painting using genomic tumor DNA as probe

A modification of reverse chromosome painting was carried out using genomic DNA from tumor cells as a complex probe for chromosomal in situ suppression hybridization to normal metaphase chromsome spreads. Amplified DNA sequences contained in such probes showed specific signals, revealing the normal chromosome positions from which these sequences were derived. As a model system, genomic DNAs were analyzed from three tumor cell lines with amplification units including the proto-oncogene c-myc. The smallest amplification unit was about 90 kb and was present in 16–24 copies; the largest unit was bigger than 600 kb and was present in 16–32 copies. Specific signals that co-localized with a differently labeled c-myc probe on chromosome band 8q24 were obtained with genomic DNA from each cell line. In further experiments, genomic DNA derived from primary tumor material was used in the case of a male patient with glioblastoma multiforme (GBM). Southern blot analysis using an epidermal growth factor receptor gene (EGFR) probe that maps to 7p13 indicated the amplification of sequences from this gene. Using reverse chromosome painting, signals were found both on band 7p13 and bands 12q13–q15. Notably, the signal on 12q13–q15 was consistently stronger. The weaker 7p13 signal showed co-localization with the major signal of the differently labeled EGFR probe. A minor signal of this probe was seen on 12q13, suggesting cross-hybridization to ERB3 sequences homologous to EGFR. The results indicate co-amplification of sequences from bands 12q13–q15, in addition to sequences from band 7p13. Several oncogenes map to 12q13–q15 providing candidate genes for a tumor-associated proto-oncogene amplification. Although the nature of the amplified sequences needs to be clarified, this experiment demonstrates the potential of reverse chromosome painting with genomic tumor DNA for rapidly mapping the normal chromosomal localization of the DNA from which the amplified sequences were derived. In addition, a weaker staining of chromosomes 10 and X was consistently observed indicating that these chromosomes were present in only one copy in the GBM genome. This rapid approach can be used to analyze cases where no metaphase spreads from the tumor material are available. It does not require any preknowledge of amplified sequences and can be applied to screen large numbers of tumors

Rationale, design and conduct of a comprehensive evaluation of a primary care based intervention to improve the quality of life of osteoarthritis patients. The PraxArt-project: a cluster randomized controlled trial [ISRCTN87252339] ; study protocol

Background: Osteoarthritis (OA) has a high prevalence in primary care. Conservative, guideline orientated approaches aiming at improving pain treatment and increasing physical activity, have been proven to be effective in several contexts outside the primary care setting, as for instance the Arthritis Self management Programs (ASMPs). But it remains unclear if these comprehensive evidence based approaches can improve patients' quality of life if they are provided in a primary care setting. Methods/Design: PraxArt is a cluster randomised controlled trial with GPs as the unit of randomisation. The aim of the study is to evaluate the impact of a comprehensive evidence based medical education of GPs on individual care and patients' quality of life. 75 GPs were randomised either to intervention group I or II or to a control group. Each GP will include 15 patients suffering from osteoarthritis according to the criteria of ACR. In intervention group I GPs will receive medical education and patient education leaflets including a physical exercise program. In intervention group II the same is provided, but in addition a practice nurse will be trained to monitor via monthly telephone calls adherence to GPs prescriptions and advices and ask about increasing pain and possible side effects of medication. In the control group no intervention will be applied at all. Main outcome measurement for patients' QoL is the GERMAN-AIMS2-SF questionnaire. In addition data about patients' satisfaction (using a modified EUROPEP-tool), medication, health care utilization, comorbidity, physical activity and depression (using PHQ-9) will be retrieved. Measurements (pre data collection) will take place in months I-III, starting in June 2005. Post data collection will be performed after 6 months. Discussion: Despite the high prevalence and increasing incidence, comprehensive and evidence based treatment approaches for OA in a primary care setting are neither established nor evaluated in Germany. If the evaluation of the presented approach reveals a clear benefit it is planned to provide this GP-centred interventions on a much larger scale

A modeling study of oceanic nitrous oxide during the Younger Dryas cold period

The marine production, cycling, and air-sea gas exchange of nitrous oxide (N2O) are simulated in a coupled climate-biogeochemical model of reduced complexity. The model gives a good representation of the large-scale features of the observed oceanic N2O distribution and emissions to the atmosphere. The transient behavior of the model is tested for the Younger Dryas (Y-D) cold period (12,700–11,550 BP), which is simulated by releasing a freshwater pulse into the North Atlantic, causing a temporary collapse of the model's Atlantic thermohaline circulation (THC). A temporary drop in atmospheric N2O of about 10 ppb results, while ice-core measurements show a total drop of 25 to 30 ppb. This suggests that terrestrial changes have also contributed to the observed variations. The main cause of the modeled reduction in atmospheric N2O is increased oceanic storage in the short-term and a reduction of new production in the long-term due to increased stratification

Revision of the global carbon budget due to changing air-sea oxygen fluxes

Carbon budgets inferred from measurements of the atmospheric oxygen to nitrogen ratio (O2/N2) are revised considering sea-to-air fluxes of O2 and N2 in response to global warming and volcanic eruptions. Observational estimates of changes in ocean heat content are combined with a model-derived relationship between changes in atmospheric O2/N2 due to oceanic outgassing and heat fluxes to estimate ocean O2 outgassing. The inferred terrestrial carbon sink for the 1990s is reduced by a factor of two compared with the most recent estimate by the Intergovernmental Panel on Climate Change (IPCC). This also improves the agreement between calculated ocean carbon uptake rates and estimates from global carbon cycle models, which indicate a higher ocean carbon uptake during the 1990s than the 1980s. The simulated decrease in oceanic O2 concentrations is in qualitative agreement with observed trends in oceanic O2 concentrations

ELSID-diabetes study-evaluation of a large scale implementation of disease management programmes for patients with type 2 diabetes. Rationale, design and conduct : a study protocol

Background: Diabetes model projects in different regions of Germany including interventions such as quality circles, patient education and documentation of medical findings have shown improvements of HbA1c levels, blood pressure and occurrence of hypoglycaemia in before-after studies (without control group). In 2002 the German Ministry of Health defined legal regulations for the introduction of nationwide disease management programs (DMP) to improve the quality of care in chronically ill patients. In April 2003 the first DMP for patients with type 2 diabetes was accredited. The evaluation of the DMP is essential and has been made obligatory in Germany by the Fifth Book of Social Code. The aim of the study is to assess the effectiveness of DMP by example of type 2 diabetes in the primary care setting of two German federal states (Rheinland-Pfalz and Sachsen-Anhalt). Methods/Design: The study is three-armed: a prospective cluster-randomized comparison of two interventions (DMP 1 and DMP 2) against routine care without DMP as control group. In the DMP group 1 the patients are treated according to the current situation within the German-Diabetes-DMP. The DMP group 2 represents diabetic care within ideally implemented DMP providing additional interventions (e.g. quality circles, outreach visits). According to a sample size calculation a sample size of 200 GPs (each GP including 20 patients) will be required for the comparison of DMP 1 and DMP 2 considering possible drop-outs. For the comparison with routine care 4000 patients identified by diabetic tracer medication and age (> 50 years) will be analyzed. Discussion: This study will evaluate the effectiveness of the German Diabetes-DMP compared to a Diabetes-DMP providing additional interventions and routine care in the primary care setting of two different German federal states

Vascular basis of mucosal color

BACKGROUND: Besides the color of the teeth the color of the alveolar gingiva plays a crucial role in esthetic rehabilitation in dento-alveolar treatment. Whereas nowadays the color of the teeth can be determined exactly and individually, the specific influence of the red color of the gingiva on treatment has not been assessed yet. The aim of this study was to evaluate the vascularization as the basis for gingival esthetics. METHODS: Standardized photographs of defined areas of the alveolar gingiva in operated and non-operated patients were taken and assigned to groups with same characteristics after color comparisons. In addition, histologic and immunohistologic analyses of gingival specimens were performed for qualitative and quantitative assessment of vessels and vascularization. Finally, colors and number of vessels were correlated. RESULTS: Our results demonstrated three different constellations of colors of the alveolar gingiva in healthy patients. The operated patients could not be grouped because of disparate depiction. There was a clear correlation between color and vessel number in the alveolar gingiva. CONCLUSION: Our investigations revealed the connections between vascularization and gingival color. Recommendations for specific change or even selection of colors based on the results cannot be given, but the importance of vascularly based incision lines was demonstrated

Distance dependence of entanglement generation via a bosonic heat bath

Within a generalized Caldeira-Leggett model we analyze the conditions under which a bosonic heat bath can entangle two microscopic quantum systems at a distance $r$. We find that the attainable entanglement is extremely distance-sensitive. Significant entanglement can only be achieved if the systems are within a {\em microscopic} distance that is of order of the cut-off wavelength $\lambda$ of the system-bath interaction. At larger distances the maximal entanglement is exponentially suppressed with a decay length of order $\lambda$. We conclude that entanglement generation via a heat bath is not suitable for entangling remote objects.Comment: 4 pages, 3 figures, new title, final version to appear in Phys. Rev. Let