Simulating and Quantifying Multiple Natural Subsea CO2 Seeps at Panarea Island (Aeolian Islands, Italy) as a Proxy for Potential Leakage from Subseabed Carbon Storage Sites.

Carbon dioxide (CO2) capture and storage (CCS) has been discussed as a potentially significant mitigation option for the ongoing climate warming. Natural CO2 release sites serve as natural laboratories to study subsea CO2 leakage in order to identify suitable analytical methods and numerical models to develop best-practice procedures for the monitoring of subseabed storage sites. We present a new model of bubble (plume) dynamics, advection-dispersion of dissolved CO2, and carbonate chemistry. The focus is on a medium-sized CO2 release from 294 identified small point sources around Panarea Island (South-East Tyrrhenian Sea, Aeolian Islands, Italy) in water depths of about 40-50 m. This study evaluates how multiple CO2 seep sites generate a temporally variable plume of dissolved CO2. The model also allows the overall flow rate of CO2 to be estimated based on field measurements of pH. Simulations indicate a release of ∼6900 t y-1 of CO2 for the investigated area and highlight an important role of seeps located at >20 m water depth in the carbon budget of the Panarea offshore gas release system. This new transport-reaction model provides a framework for understanding potential future leaks from CO2 storage sites.

Mobile underwater in situ gamma-ray spectroscopy to localize groundwater emanation from pockmarks in the Eckernförde bay, Germany.

Eckernförde Bay in the Baltic Sea is well-known for the pockmarks areas which are located in the centre and off the southern shore-line of the bay emanating groundwater in a non-continuous but episodic way. Mobile underwater in situ gamma-ray spectroscopy is exploited proving that both 214Bi and 40K are efficient radiotracers for localization of seepage areas whenever either sediment is in mixture with the emanating fluid or resuspension of surface sediment occurs as a side effect of the fluid emanation.

Shallow Gas Migration along Hydrocarbon Wells-An Unconsidered, Anthropogenic Source of Biogenic Methane in the North Sea.

Shallow gas migration along hydrocarbon wells constitutes a potential methane emission pathway that currently is not recognized in any regulatory framework or greenhouse gas inventory. Recently, the first methane emission measurements at three abandoned offshore wells in the Central North Sea (CNS) were conducted showing that considerable amounts of biogenic methane originating from shallow gas accumulations in the overburden of deep reservoirs were released by the boreholes. Here, we identify numerous wells poking through shallow gas pockets in 3-D seismic data of the CNS indicating that about one-third of the wells may leak, potentially releasing a total of 3-17 kt of methane per year into the North Sea. This poses a significant contribution to the North Sea methane budget. A large fraction of this gas (∼42%) may reach the atmosphere via direct bubble transport (0-2 kt yr-1) and via diffusive exchange of methane dissolving in the surface mixed layer (1-5 kt yr-1), as indicated by numerical modeling. In the North Sea and in other hydrocarbon-prolific provinces of the world shallow gas pockets are frequently observed in the sedimentary overburden and aggregate leakages along the numerous wells drilled in those areas may be significant.

Differences in pain perception during open muscle biopsy and Bergstroem needle muscle biopsy.

PURPOSE: Open surgical muscle biopsy (OB) and percutaneous Bergstroem needle muscle biopsy (NB) are equally accepted procedures. However, there are no data comparing intraprocedural pain for both techniques. We designed this prospective trial to test the hypothesis that the less invasive NB causes less intraprocedural pain than OB. METHODS: In a two-center prospective trial, 33 patients underwent both procedures in one session. All patients quantified intraprocedural pain using the numeric rating scale (NRS). Mean NRS values were calculated along with the difference in NRS values (ΔNRS) between both types of biopsies. RESULTS: Mean NRS values were 4.5 (±2.7 standard deviation [SD]) for NB and 3.2 (±2.1) for OB (P=0.02). Of the patients, 57.6% described the ΔNRS as ≤2 NRS points. Regarding the pain categories "mild" (NRS 0-3), "moderate" (NRS 4-7), and "severe" (NRS 8-10), no significant difference was observed between NB and OB. Patients who found NB to be more uncomfortable were more likely to quantify the ΔNRS as >2 NRS points than patients finding OB more uncomfortable. CONCLUSION: Our results do not support the hypothesis that intraprocedural pain in NB is less than in OB. When informing the patient about both types of muscle biopsies, the amount of intraprocedural pain should not serve as a differentiating characteristic.

Methane-carbon flow into the benthic food web at cold seeps--a case study from the Costa Rica subduction zone.

Cold seep ecosystems can support enormous biomasses of free-living and symbiotic chemoautotrophic organisms that get their energy from the oxidation of methane or sulfide. Most of this biomass derives from animals that are associated with bacterial symbionts, which are able to metabolize the chemical resources provided by the seeping fluids. Often these systems also harbor dense accumulations of non-symbiotic megafauna, which can be relevant in exporting chemosynthetically fixed carbon from seeps to the surrounding deep sea. Here we investigated the carbon sources of lithodid crabs (Paralomis sp.) feeding on thiotrophic bacterial mats at an active mud volcano at the Costa Rica subduction zone. To evaluate the dietary carbon source of the crabs, we compared the microbial community in stomach contents with surface sediments covered by microbial mats. The stomach content analyses revealed a dominance of epsilonproteobacterial 16S rRNA gene sequences related to the free-living and epibiotic sulfur oxidiser Sulfurovum sp. We also found Sulfurovum sp. as well as members of the genera Arcobacter and Sulfurimonas in mat-covered surface sediments where Epsilonproteobacteria were highly abundant constituting 10% of total cells. Furthermore, we detected substantial amounts of bacterial fatty acids such as i-C15∶0 and C17∶1ω6c with stable carbon isotope compositions as low as -53‰ in the stomach and muscle tissue. These results indicate that the white microbial mats at Mound 12 are comprised of Epsilonproteobacteria and that microbial mat-derived carbon provides an important contribution to the crab's nutrition. In addition, our lipid analyses also suggest that the crabs feed on other (13)C-depleted organic matter sources, possibly symbiotic megafauna as well as on photosynthetic carbon sources such as sedimentary detritus.

Severe loss of appetite in amyotrophic lateral sclerosis patients: online self-assessment study.

BACKGROUND: Undesirable loss of weight is a major challenge in amyotrophic lateral sclerosis (ALS). However, little is known about loss of appetite in ALS patients. OBJECTIVE: We investigated loss of appetite in ALS patients by means of an online self-assessment and whether ALS-related symptoms were associated with it. METHODS: Loss of appetite in 51 ALS patients was assessed using the Council on Nutrition Appetite Questionnaire (CNAQ). Loss of appetite is defined as a CNAQ-score of 28 or less with a predicted weight loss of at least 5% within 6 months. We developed an Internet portal to facilitate self-assessment. RESULTS: Approximately half of the ALS patients (47%, 24/51) suffered from severe loss of appetite; after 6 months this increased to nearly two-thirds (65%, 22/34). An average weight loss of 5% was found in the group with severe loss of appetite as compared to only 2% of patients with normal appetite. Interestingly, loss of appetite was associated with respiratory dysfunction (P=.001, R(2)=.223). CONCLUSIONS: Loss of appetite was more common and more severe than expected. It was found to be an independent risk factor for unintended weight loss and may be related to dyspnea. The impact of severe loss of appetite on survival and quality of life should be established in further studies.

Online assessment of ALS functional rating scale compares well to in-clinic evaluation: a prospective trial.

Self-assessment of symptom progression in chronic diseases is of increasing importance in clinical research, patient management and specialized outpatient care. Against this background, we developed a secure internet platform (ALShome.de) that allows online assessment of the revised ALS Functional Rating Scale (ALSFRS-R) and other established self-assessment questionnaires. We developed a secure and closed internet portal to assess patient reported outcomes. In a prospective, controlled and stratified study, patients conducted a web-based self-assessment of ALSFRS-R compared to on-site assessment. On-site and online assessments were compared at baseline (n = 127) and after 3.5 months (n = 81, 64%). Results showed that correlation between on-site evaluation and online testing of ALSFRS-R was highly significant (r = 0.96; p < 0.001). The agreement of both capturing methods (online vs. on-site) was excellent (mean interval, 8.8 days). The adherence to online rating was high; 75% of patients tested on-site completed a follow-up online visit (mean 3.5 months, SD 1.7). We conclude that online self-assessment of ALS severity complements the well-established face-to-face application of the ALSFRS-R during on-site visits. The results of our study support the use of online administration of ALSFRS-R within clinical trials and for managing the care of ALS patients.

Thalidomide causes sinus bradycardia in ALS.

OBJECTIVE: Neuroinflammation contributes to motor neuron degeneration in ALS. Thalidomide (THL) shows potent anti-inflammatory properties and increased the lifespan in ALS transgenic mice. Thalidomide was therefore suggested as atherapeutic intervention for the treatment of ALS.We conducted a pilot, randomized clinical trial of THL in patients with ALS to assess safety, feasibility, and preliminary estimates of treatment efficacy. METHODS: Patients were randomized to THL in combination with riluzole (n = 18) or riluzole alone (n = 19). THL was initiated at 100 mg per day for 6 weeks. Thereafter, the dose was increased every week by 50 mg until reaching the dose of 400 mg per day and planned to continue for another 12 weeks. RESULTS: Within 12 weeks of THL treatment, nine THL patients (50%) developed bradycardia defined as a heart rate below 60 beats per minute (bpm) and ranged from 46 to 59 bpm. Mean heart rate dropped by 17 bpm with THL treatment. Severe symptomatic bradycardia of 30 bpm occurred in one patient. A further patient died from sudden unexpected death. The study was terminated prematurely for safety concerns. The secondary outcome variables showed similar results for both groups. CONCLUSION: Bradycardia was the most common adverse event of THL treatment in ALS. THL-related bradycardia does not appear to be ALS-specific. It is conceivable, however, that the unexpected frequency and severity of THL-induced bradycardia may be related to subclinical involvement of the autonomic nervous system in ALS. The cardiac toxicity discourages further clinical trials and compassionate use of THL in ALS. ClinicalTrials.gov Identifier: NCT00231140.

Progressive muscle atrophy with hypokalemic periodic paralysis and calcium channel mutation.

A family with hypokalemic periodic paralysis (HypoPP) and motor neuron degeneration is reported. In conjunction with HypoPP, the index patient developed progressive muscle atrophy. The calcium channel gene CACNA1S showed a mutation encoding p.R528H, which has been related previously to HypoPP. We propose that CACNA1S mutations may comprise a previously unrecognized genetic risk factor in a greater spectrum of motor unit disorders including amyotrophic lateral sclerosis.

Frequency of a tau genotype in amyotrophic lateral sclerosis.

We investigated the susceptibility of the dinucleotide polymorphism A0 in the tau gene to amyotrophic lateral sclerosis (ALS). In 416 unrelated patients with ALS and 242 control subjects the A0/A0 genotype was not associated with the pooled sample of ALS cases. Subgroup analysis revealed that in sporadic ALS the A0 polymorphism was significantly overrepresented. There was no association of the A0/A0 genotype with the age and site of disease onset or the presence of dementia. The studied tau genotype may contribute to the multifactorial genetic background of ALS.