Methane emissions from floodplains in the Amazon Basin: challenges in developing a process-based model for global applications

Tropical wetlands are estimated to represent about 50% of the natural wetland methane (CH4) emissions and explain a large fraction of the observed CH4 variability on timescales ranging from glacial–interglacial cycles to the currently observed year-to-year variability. Despite their importance, however, tropical wetlands are poorly represented in global models aiming to predict global CH4 emissions. This publication documents a first step in the development of a process-based model of CH4 emissions from tropical floodplains for global applications. For this purpose, the LPX-Bern Dynamic Global Vegetation Model (LPX hereafter) was slightly modified to represent floodplain hydrology, vegetation and associated CH4 emissions. The extent of tropical floodplains was prescribed using output from the spatially explicit hydrology model PCR-GLOBWB. We introduced new plant functional types (PFTs) that explicitly represent floodplain vegetation. The PFT parameterizations were evaluated against available remote-sensing data sets (GLC2000 land cover and MODIS Net Primary Productivity). Simulated CH4 flux densities were evaluated against field observations and regional flux inventories. Simulated CH4 emissions at Amazon Basin scale were compared to model simulations performed in the WETCHIMP intercomparison project. We found that LPX reproduces the average magnitude of observed net CH4 flux densities for the Amazon Basin. However, the model does not reproduce the variability between sites or between years within a site. Unfortunately, site information is too limited to attest or disprove some model features. At the Amazon Basin scale, our results underline the large uncertainty in the magnitude of wetland CH4 emissions. Sensitivity analyses gave insights into the main drivers of floodplain CH4 emission and their associated uncertainties. In particular, uncertainties in floodplain extent (i.e., difference between GLC2000 and PCR-GLOBWB output) modulate the simulated emissions by a factor of about 2. Our best estimates, using PCR-GLOBWB in combination with GLC2000, lead to simulated Amazon-integrated emissions of 44.4 ± 4.8 Tg yr−1. Additionally, the LPX emissions are highly sensitive to vegetation distribution. Two simulations with the same mean PFT cover, but different spatial distributions of grasslands within the basin, modulated emissions by about 20%. Correcting the LPX-simulated NPP using MODIS reduces the Amazon emissions by 11.3%. Finally, due to an intrinsic limitation of LPX to account for seasonality in floodplain extent, the model failed to reproduce the full dynamics in CH4 emissions but we proposed solutions to this issue. The interannual variability (IAV) of the emissions increases by 90% if the IAV in floodplain extent is accounted for, but still remains lower than in most of the WETCHIMP models. While our model includes more mechanisms specific to tropical floodplains, we were unable to reduce the uncertainty in the magnitude of wetland CH4 emissions of the Amazon Basin. Our results helped identify and prioritize directions towards more accurate estimates of tropical CH4 emissions, and they stress the need for more research to constrain floodplain CH4 emissions and their temporal variability, even before including other fundamental mechanisms such as floating macrophytes or lateral water fluxes.

Spatial-temporal clustering of companion animal enteric syndrome: detection and investigation through the use of electronic medical records from participating private practices

SUMMARY There is interest in the potential of companion animal surveillance to provide data to improve pet health and to provide early warning of environmental hazards to people. We implemented a companion animal surveillance system in Calgary, Alberta and the surrounding communities. Informatics technologies automatically extracted electronic medical records from participating veterinary practices and identified cases of enteric syndrome in the warehoused records. The data were analysed using time-series analyses and a retrospective space-time permutation scan statistic. We identified a seasonal pattern of reports of occurrences of enteric syndromes in companion animals and four statistically significant clusters of enteric syndrome cases. The cases within each cluster were examined and information about the animals involved (species, age, sex), their vaccination history, possible exposure or risk behaviour history, information about disease severity, and the aetiological diagnosis was collected. We then assessed whether the cases within the cluster were unusual and if they represented an animal or public health threat. There was often insufficient information recorded in the medical record to characterize the clusters by aetiology or exposures. Space-time analysis of companion animal enteric syndrome cases found evidence of clustering. Collection of more epidemiologically relevant data would enhance the utility of practice-based companion animal surveillance.

Considerations for prenatal counselling of patients with cardiac rhabdomyomas based on their cardiac and neurologic outcomes

Cardiac rhabdomyomas are benign cardiac tumours with few cardiac complications, but with a known association to tuberous sclerosis that affects the neurologic outcome of the patients. We have analysed the long-term cardiac and neurological outcomes of patients with cardiac rhabdomyomas in order to allow comprehensive prenatal counselling, basing our findings on the records of all patients seen prenatally and postnatally with an echocardiographic diagnosis of cardiac rhabdomyoma encountered from August, 1982, to September, 2007. We analysed factors such as the number and the location of the tumours to establish their association with a diagnosis of tuberous sclerosis, predicting the cardiac and neurologic outcomes for the patients.Cardiac complications include arrhythmias, obstruction of the ventricular outflow tracts, and secondary cardiogenic shock. Arrhythmias were encountered most often during the neonatal period, with supraventricular tachycardia being the commonest rhythm disturbance identified. No specific dimension or location of the cardiac rhabdomyomas predicted the disturbances of rhythm.The importance of the diagnosis of tuberous sclerosis is exemplified by the neurodevelopmental complications, with four-fifths of the patients showing epilepsy, and two-thirds having delayed development. The presence of multiple cardiac tumours suggested a higher risk of being affected by tuberous sclerosis. The tumours generally regress after birth, and cardiac-related problems are rare after the perinatal period. Tuberous sclerosis and the associated neurodevelopmental complications dominate the clinical picture, and should form an important aspect of the prenatal counselling of parents.

Hierarchical clustering of flow cytometry data for the study of conventional central chondrosarcoma

We have investigated the use of hierarchical clustering of flow cytometry data to classify samples of conventional central chondrosarcoma, a malignant cartilage forming tumor of uncertain cellular origin, according to similarities with surface marker profiles of several known cell types. Human primary chondrosarcoma cells, articular chondrocytes, mesenchymal stem cells, fibroblasts, and a panel of tumor cell lines from chondrocytic or epithelial origin were clustered based on the expression profile of eleven surface markers. For clustering, eight hierarchical clustering algorithms, three distance metrics, as well as several approaches for data preprocessing, including multivariate outlier detection, logarithmic transformation, and z-score normalization, were systematically evaluated. By selecting clustering approaches shown to give reproducible results for cluster recovery of known cell types, primary conventional central chondrosacoma cells could be grouped in two main clusters with distinctive marker expression signatures: one group clustering together with mesenchymal stem cells (CD49b-high/CD10-low/CD221-high) and a second group clustering close to fibroblasts (CD49b-low/CD10-high/CD221-low). Hierarchical clustering also revealed substantial differences between primary conventional central chondrosarcoma cells and established chondrosarcoma cell lines, with the latter not only segregating apart from primary tumor cells and normal tissue cells, but clustering together with cell lines from epithelial lineage. Our study provides a foundation for the use of hierarchical clustering applied to flow cytometry data as a powerful tool to classify samples according to marker expression patterns, which could lead to uncover new cancer subtypes.

Segmentation of brain tumor images based on atlas-registration combined with a Markov-Random-Field lesion growth model

We present an automatic method to segment brain tissues from volumetric MRI brain tumor images. The method is based on non-rigid registration of an average atlas in combination with a biomechanically justified tumor growth model to simulate soft-tissue deformations caused by the tumor mass-effect. The tumor growth model, which is formulated as a mesh-free Markov Random Field energy minimization problem, ensures correspondence between the atlas and the patient image, prior to the registration step. The method is non-parametric, simple and fast compared to other approaches while maintaining similar accuracy. It has been evaluated qualitatively and quantitatively with promising results on eight datasets comprising simulated images and real patient data.

Dissecting Carotenoid from Structural Components of Carotenoid-Based Coloration: A Field Experiment with Great Tits (Parus major)

Carotenoid-based yellowish to red plumage colors are widespread visual signals used in sexual and social communication. To understand their ultimate signaling functions, it is important to identify the proximate mechanism promoting variation in coloration. Carotenoid-based colors combine structural and pigmentary components, but the importance of the contribution of structural components to variation in pigment-based colors (i.e., carotenoid-based colors) has been undervalued. In a field experiment with great tits (Parus major), we combined a brood size manipulation with a simultaneous carotenoid supplementation in order to disentangle the effects of carotenoid availability and early growth condition on different components of the yellow breast feathers. By defining independent measures of feather carotenoid content (absolute carotenoid chroma) and background structure (background reflectance), we demonstrate that environmental factors experienced during the nestling period, namely, early growth conditions and carotenoid availability, contribute independently to variation in yellow plumage coloration. While early growth conditions affected the background reflectance of the plumage, the availability of carotenoids affected the absolute carotenoid chroma, the peak of maximum ultraviolet reflectance, and the overall shape, that is, chromatic information of the reflectance curves. These findings demonstrate that environment-induced variation in background structure contributes significantly to intraspecific variation in yellow carotenoid-based plumage coloration.

Urban Expansion and its impact on urban agriculture - remote sensing based change analysis of Kizinga and Mzinga Valley - Dar Es Salaam, Tanzania

Urban agriculture is a phenomenon that can be observed world-wide, particularly in cities of devel- oping countries. It is contributing significantly to food security and food safety and has sustained livelihood of the urban and peri-urban low income dwe llers in developing countries for many years. Population increase due to rural-urban migration and natural - formal as well as informal - urbani- sation are competing with urban farming for available space and scarce water resources. A mul- titemporal and multisensoral urban change analysis over the period of 25 years (1982-2007) was performed in order to measure and visualise the urban expansion along the Kizinga and Mzinga valley in the south of Dar Es Salaam. Airphotos and VHR satellite data were analysed by using a combination of a composition of anisotropic textural measures and spectral information. The study revealed that unplanned built-up area is expanding continuously, and vegetation covers and agricultural lands decline at a fast rate. The validation showed that the overall classification accuracy varied depending on the database. The extracted built-up areas were used for visual in- terpretation mapping purposes and served as information source for another research project. The maps visualise an urban congestion and expansion of nearly 18% of the total analysed area that had taken place in the Kizinga valley between 1982 and 2007. The same development can be ob- served in the less developed and more remote Mzinga valley between 1981 and 2002. Both areas underwent fast changes where land prices still tend to go up and an influx of people both from rural and urban areas continuously increase the density with the consequence of increasing multiple land use interests.

Beneficial effects of aggressive low-density lipoprotein cholesterol lowering in women with stable coronary heart disease in the Treating to New Targets (TNT) study

OBJECTIVE: To examine by secondary analysis of the Treating to New Targets (TNT) study whether the benefits of intensive versus standard levels of lipid lowering are equally applicable to women. METHODS: A total of 10 001 patients (1902 women) with stable coronary heart disease (CHD) were randomised to double-blind treatment with atorvastatin 10 or 80 mg/day for a median follow-up of 4.9 years. RESULTS: In women and men, intensive treatment with atorvastatin 80 mg significantly reduced the rate of major cardiovascular events compared with atorvastatin 10 mg. Among women, the relative and absolute reductions were 27% and 2.7%, respectively (hazard ratio (HR) = 0.73, 95% confidence interval (CI) 0.54 to 1.00, p = 0.049). In men, the corresponding rate reductions were 21% and 2.2% (HR = 0.79, 95% CI 0.69 to 0.91, p = 0.001). The number needed to treat value (to prevent one cardiovascular event over 4.9 years compared with patients treated with atorvastatin 10 mg) for atorvastatin 80 mg was 29 for women and 30 for men. Rates of death of non-cardiovascular origin in the atorvastatin 80 mg and atorvastatin 10 mg were 3.6% and 1.6%, respectively (p = 0.004) among women, and 2.8% and 3.1% (p = 0.47) among men. CONCLUSION: Intensive lipid-lowering treatment with atorvastatin 80 mg produced significant reductions in relative risk for major cardiovascular events compared with atorvastatin 10 mg in both women and men with stable CHD.

Intellectual outcome, motor skills and BMI of children with congenital hypothyroidism: a population-based study

AIM: To evaluate intellectual outcome, motor skills and anthropometric data of children with congenital hypothyroidism (CH). METHODS: Children with permanent CH who were born in 1999 in Bavaria were eligible for this prospective, population-based study. Cognitive performance was evaluated by the Kaufman Assessment Battery for Children and motor skills were assessed by the motor test, Motoriktest für vier-bis sechsjahrige Kinder (MOT) 4-6. RESULTS: Eighteen of 21 eligible children participated (86%). Median age of the children was 5.5 years (range 4.9-5.8). Treatment with levothyroxine was started after a median of 7.2 days (range 4-15) with a median dose of 12.0 microg/kg (range 7.2-17.0). Mean intelligence quotient (IQ) of the children was 100.4 (standard deviation [SD] 10.1): no children had IQ values below the normal range. Reactivity and speed of movement were significantly reduced in children with CH. Children with an initial thyroid-stimulating hormone (TSH) value of >200 mU/L performed significantly worse than children with TSH value of with CH had a significant increased risk for overweight (risk ratio [RR] 3.91, 95% confidence interval [CI] 1.22-11.75, p=0.005) compared to the Bavarian reference children. CONCLUSION: In this study, children with CH had an increased prevalence of overweight compared to reference data. Partially impaired motor skills could be shown, whereas the intellectual development was normal.

Evaluation of a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-conjugated bombesin-based radioantagonist for the labeling with single-photon emission computed tomography, positron emission tomography, and therapeutic radionuclides

PURPOSE: G protein-coupled receptor agonists are being used as radiolabeled vectors for in vivo localization and therapy of tumors. Recently, somatostatin-based antagonists were shown to be superior to agonists. Here, we compare the new [111In/68Ga]-labeled bombesin-based antagonist RM1 with the agonist [111In]-AMBA for targeting the gastrin-releasing peptide receptor (GRPR). EXPERIMENTAL DESIGN: IC50, Kd values, and antagonist potency were determined using PC-3 and HEK-GRPR cells. Biodistribution and imaging studies were done in nude mice transplanted with the PC-3 tumor. The antagonist potency was assessed by evaluating the effects on calcium release and on receptor internalization monitored by immunofluorescence microscopy. RESULTS: The IC50 value of [(nat)In]-RM1 was 14 +/- 3.4 nmol/L. [(nat/111)In]-RM1 was found to bind to the GRPR with a Kd of 8.5 +/- 2.7 nmol/L compared with a Kd of 0.6 +/- 0.3 nmol/L of [111In]-AMBA. A higher maximum number of binding site value was observed for [111In]-RM1 (2.4 +/- 0.2 nmol/L) compared with [111In]-AMBA (0.7 +/- 0.1 nmol/L). [(nat)Lu]-AMBA is a potent agonist in the immunofluorescence-based internalization assay, whereas [(nat)In]-RM1 is inactive alone but efficiently antagonizes the bombesin effect. These data are confirmed by the calcium release assay. The pharmacokinetics showed a superiority of the radioantagonist with regard to the high tumor uptake (13.4 +/- 0.8% IA/g versus 3.69 +/- 0.75% IA/g at 4 hours after injection. as well as to all tumor-to-normal tissue ratios. CONCLUSION: Despite their relatively low GRPR affinity, the antagonists [111In/68Ga]-RM1 showed superior targeting properties compared with [111In]-AMBA. As found for somatostatin receptor-targeting radiopeptides, GRP-based radioantagonists seem to be superior to radioagonists for in vivo imaging and potentially also for targeted radiotherapy of GRPR-positive tumors.

[Bone density and laboratory parameters of bone metabolism in patients with terminal heart disease]

The purpose of this study was to assess bone mineral density (BMD) and parameters for bone metabolism in patients with end-stage heart disease awaiting heart transplantation to determine whether these patients are at increased risk of bone disease.

Phylogenetic analysis of Prevotella nigrescens, Prevotella intermedia and Porphyromonas gingivalis clinical strains reveals a clear species clustering

Prevotella nigrescens, Prevotella intermedia and Porphyromonas gingivalis are oral pathogens from the family Bacteroidaceae, regularly isolated from cases of gingivitis and periodontitis. In this study, the phylogenetic variability of these three bacterial species was investigated by means of 16S rRNA (rrs) gene sequence comparisons of a set of epidemiologically and geographically diverse isolates. For each of the three species, the rrs gene sequences of 11 clinical isolates as well as the corresponding type strains was determined. Comparison of all rrs sequences obtained with those of closely related species revealed a clear clustering of species, with only a little intraspecies variability but a clear difference in the rrs gene with respect to the next related taxon. The results indicate that the three species form stable, homogeneous genetic groups, which favours an rrs-based species identification of these oral pathogens. This is especially useful given the 7% sequence divergence between Prevotella intermedia and Prevotella nigrescens, since phenotypic distinction between the two Prevotella species is inconsistent or involves techniques not applicable in routine identification.