Structural controls on the location and distribution of CO2 emission at a natural CO2 spring in Daylesford, Australia

Secure storage of CO2 is imperative for carbon capture and storage technology, and relies on a thorough understanding of the mechanisms of CO2 retention and leakage. Observations at CO2 seeps around the world find that geological structures at a local and regional scale control the location, distribution and style of CO2 emission. Bedrock-hosted natural CO2 seepage is found in the Daylesford region in Victoria, Australia, where many natural springs contain high concentrations of dissolved CO2. Within a few meters of the natural Tipperary Mineral Spring, small CO2 bubble streams are emitted from bedrock into an ephemeral creek. We examine the relationship between structures in the exposed adjacent outcropping rocks and characteristics of CO2 gas leakage in the stream, including CO2 flux and the distribution of gas emissions. We find that degassing is clustered within ~1 m of a shale-sandstone geological contact. CO2 emission points are localised along bedding and fracture planes, and concentrated where these features intersect. The bubble streams were intermittent, which posed difficulties in quantifying total emitted CO2. Counterintuitively, the number of bubble streams and CO2 flux was greatest from shale dominated rather than the sandstone dominated features, which forms the regional aquifer. Shallow processes must be increasing the shale permeability, thus influencing the CO2 flow pathway and emission locations. CO2 seepage is not limited to the pool; leakage was detected in subaerial rock exposures, at the intersection of bedding and orthogonal fractures. These insights show the range of spatial scales of the geological features that control CO2 flow. Microscale features and near surface processes can have significant effect on the style and location and rates of CO2 leakage. The intermittency of the bubble streams highlights challenges around characterising and monitoring CO2 stores where seepage is spatially and temporally variable. CCS monitoring programmes must therefore be informed by understanding of shallow crustal processes and not simply the processes and pathways governing CO2 fluid flow at depth. Understanding how the CO2 fluids leaked by deep pathways might be affected by shallow processes will inform the design of appropriate monitoring tools and monitoring locations

Patterns in the occurrence of fecal bacterial indicators at Public Mineral Springs of Central Victoria, 1986-2013

In central Victoria monitoring of the fecal indicators Total Coliform and Escherichia Coliform at around 50 mineral spring sites over a period of more than three decades show distinct patterns in contamination. Criteria for examination include both the count levels and occurrence of positive readings. Initially, the springs were unsanitary dug wells, pits, and shallow 3-7 m deep bores. To overcome the recidivism, a replacement program utilizing 30-150 m deep bores was initiated. All the springs had been sited near evidence of subaqueous discharge or exfiltration of mineralized water in the base of highland valleys. Mineral water evolves and circulates in conductive fissure fault and joint systems in the bedrock. Historically a gold-mining region, nearly all sites owe their discovery to alluvial mining activities. Situated in seasonally active mixing zones at the confluence of flow systems, the vulnerability has been reflected in both the development technique and the bacteriological ambience. Catchment use, forest practices, urbanization, subdivision, and the increasing sewerage backlog in settled areas now contribute to a fecal bacterial load in the catchments of the springs and, in particular, the proximal streams and gullies. Within the data set, distinct seasonal patterns appear in the presence, count, ratio between indicators, and/or the absence of fecal bacteria. Spring contamination and bacterial predominance correlate with seasonal catchment hydrodynamics, in spite of event-related episodes. Deep replacement bores reduce or extinguish the occurrence of scherichia Coliform, while some sites may return positive Total Coliform counts, which suggests the need for disinfection during maintenance procedures. © 2023 American Geophysical Union

Calcium/Calmodulin-Dependent Protein Kinase II Regulation of the Slow Delayed Rectifier Potassium Current, I(ks), During Sustained Beta-Adrenergic Receptor Stimulation

Background: Sustained elevations in catecholaminergic signaling, mediated primarily through β-adrenergic receptor (β-AR) stimulation, are a hallmark neurohormonal alteration in heart failure (HF) that contribute to pathophysiologic cardiac remodeling. An important pathophysiological change during sustained β-AR stimulation is functional inhibition of the slow delayed rectifier potassium current, IKs, which has been demonstrated to prolong action potential duration (APD) and increase ventricular arrhythmogenesis in HF. Though functional inhibition of IKs has been consistently reproduced in cellular, animal, and limited human studies of HF, the mechanisms that mediate IKs inhibition during HF remain poorly understood. In addition, HF results in aberrant calcium handling that is known to contribute to the disease. HF has been demonstrated to increase the expression and function of calcium/calmodulin-dependent protein kinase II (CaMKII), a key regulator of calcium homeostasis and excitation-contraction coupling in cardiomyocytes. Enhanced CaMKII signaling has been consistently demonstrated to contribute to increased arrhythmogenesis in a number of cardiac diseases, including HF. CaMKII is a known pathological regulator of many cardiac ion channels resulting in APD prolongation and the development of arrhythmias. Objective: This investigation aims to assesses the potential for CaMKII regulation of KCNQ1 (pore-forming subunit of IKs) during sustained β-AR stimulation and to characterize the potential functional implications on IKs. Furthermore, this investigation seeks to elucidate the mechanism underlying CaMKII-mediated IKs inhibition during sustained β-AR stimulation. Methods: Phosphorylation of KCNQ1 was assessed using a tandem liquid chromatography- mass spectrometry/ mass spectrometry (LCMS/MS) approach during sustained β-AR stimulation via treatment with 100 nM isoproterenol (ISO) for 4-24 hours and during co-expression with KCNE1. Whole-cell, voltage-clamp patch clamp electrophysiology experiments were performed in HEK 293 cells transiently co-expressing wild-type (WT) or mutant KCNQ1 (mutations conferring mimics of dephosphorylation and phosphorylation were introduced at phosphorylation sites identified by LCMS/MS) and KCNE1 (auxiliary subunit) during ISO treatment, treatment with CaMKII or protein kinase A (PKA) inhibitors, or during lentiviral δCaMKII overexpression. A robotic peptide synthesizer was used to create fifteen residue peptide fragments on a nitrocellulose membrane corresponding to KCNQ1 intracellular domains and the KCNQ1 residues identified via LCMS/MS; membranes were incubated with activated CaMKII or PKA in the presence of radiolabeled ATP to identify potential sites of phosphorylation. Bimolecular fluorescence complementation (BiFC) experiments were performed in HEK 293 cells to assess the impact of CaMKII-mediated KCNQ1 phosphorylation on the interaction of KCNQ1 and KCNE1 subunits. Protein immunoblot experiments were performed to (1) assess CaMKII activation during ISO treatment and (2) to assess plasma membrane expression of KCNQ1 and KCNE1 subunits with mimics of differential KCNQ1 phosphorylation following a membrane protein biotinylation procedure. Results: In Aim 1, we investigated the regulation of the KCNQ1 carboxyl terminus during sustained β-AR stimulation and assessed the associated functional implications on IKs. An LCMS/MS approach identified five novel KCNQ1 carboxyl terminal sites that demonstrated basal phosphorylation, with T482 and S484 having enhanced phosphorylation during treatment with 100 nM ISO for 24 hours (p\u3c0.01 at both sites). Using patch clamp electrophysiology, we demonstrated that treatment with 100 nM ISO for 12-24 hours reduced IKs current density (p=0.01) and produced a depolarizing shift in the voltage dependence of activation (p\u3c0.01) relative to vehicle

Guidelines for the use of infant formulas to treat cows milk protein allergy: an Australian consensus panel opinion

Three types of infant formula (soy, extensively hydrolysed and amino acid) may be appropriate for treating cows milk protein allergy. Selection of a formula depends on the allergy syndrome to be treated. Extensively hydrolysed formula is recommended as first choice for infants under 6 months of age for treating immediate cows milk allergy (non-anaphylactic), food protein-induced enterocolitis syndrome, atopic eczema, gastrointestinal symptoms and food protein-induced proctocolitis. Soy formula is recommended as first choice for infants over 6 months of age with immediate food reactions, and for those with gastrointestinal symptoms or atopic dermatitis in the absence of failure to thrive. Amino acid formula is recommended as first choice in anaphylaxis and eosinophilic oesophagitis. If treatment with the initial formula is not successful, use of an alternative formula is recommended.Andrew S. Kemp, David J. Hill, Katrina J. Allen, Kym Anderson, Geoffrey P. Davidson, Andrew S. Day, Ralph G. Heine, Jane E. Peake, Susan L. Prescott, Albert W. Shugg and John K. Sin

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic : an international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Delaying surgery for patients with a previous SARS-CoV-2 infection

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