Hydrogen and dark oxygen drive microbial productivity in diverse groundwater ecosystems.

Around 50% of humankind relies on groundwater as a source of drinking water. Here we investigate the age, geochemistry, and microbiology of 138 groundwater samples from 95 monitoring wells (<250 m depth) located in 14 aquifers in Canada. The geochemistry and microbiology show consistent trends suggesting large-scale aerobic and anaerobic hydrogen, methane, nitrogen, and sulfur cycling carried out by diverse microbial communities. Older groundwaters, especially in aquifers with organic carbon-rich strata, contain on average more cells (up to 1.4 × 107 mL-1) than younger groundwaters, challenging current estimates of subsurface cell abundances. We observe substantial concentrations of dissolved oxygen (0.52 ± 0.12 mg L-1 [mean ± SE]; n = 57) in older groundwaters that seem to support aerobic metabolisms in subsurface ecosystems at an unprecedented scale. Metagenomics, oxygen isotope analyses and mixing models indicate that dark oxygen is produced in situ via microbial dismutation. We show that ancient groundwaters sustain productive communities and highlight an overlooked oxygen source in present and past subsurface ecosystems of Earth.

The impact of a magnetic field on electrode fouling during electrocoagulation.

Electrocoagulation (EC) in water treatment encounters several challenges, such as electrode fouling and passivation, especially when the effluent has a complex composition, such as produced water in the oil and gas industry. In this study, the effectiveness of applying an external magnetic field during EC with aluminum anodes (Al-EC) or mild steel anodes (Fe-EC) was investigated for the first time for the removal of inorganic contaminants (including silica, calcium, magnesium, and sulfide) from synthetic and field samples of produced waters. For Al-EC, the presence of a magnetic field perpendicular to the electric field was found to enhance the treatment performance and mitigate the fouling formation on the electrode surface. Chronoamperometric investigations indicated that the application of MF in Al-EC enhances the current density and reduces the time to form a fouling layer on the electrode. In contrast, with Fe-EC, the presence of the magnetic field increased the rate of fouling on the electrodes. Potentiodynamic and kinetic investigations indicate that the magnetic field improves mass transfer via Kelvin force and magnetohydrodynamic (MHD) effects with no impact on the type of kinetic model, while the change in the spin states of the accumulated species has a negligible impact on reducing the fouling. The resistivity of the accumulated fouling layer (δRF) was found to reduce by around 23% due to a magnetic field of 0.158 T. Although increasing the strength of the applied MF increases the mass transfer, the effect is not linear. The results indicate that applying a magnetic field in Al-EC can be an effective method to mitigate fouling during water treatment.

Investigation of electrode passivation during electrocoagulation treatment with aluminum electrodes for high silica content produced water.

One of the main challenges for the implementation of electrocoagulation (EC) in water treatment are fouling and passivation of the electrodes, especially for applications with high contaminant concentrations. For the first time, we investigated in this study the process of fouling mitigation by polarity reversal during the EC treatment of boiler blowdown water from oil-sands produced water, characterized by high silica concentrations (0.5-4 g L-1). This effluent is typically obtained from an evaporative desalination process in oil production industries. Potentiodynamic characterisation was used to study the impact of passivation on the anode dissolution. Although a charge loading of 4,800 C L-1 was found to remove about 98% of silica from a 1 L batch of 4 g L-1 Si solution, fouling reduced the performance significantly to about 40% in consecutive cycles of direct current EC (DC-EC) treatment. Periodic polarity reversal (PR) was found to reduce the amount of electrode fouling. Decreasing the polarity period from 60 to 10 s led to the formation of a soft powdery fouling layer that was easily removed from the electrodes. In contrast, with DC operation, a hard scale deposit was observed. The presence of organics in the field samples did not significantly affect the Si removal, and organics with high levels of oxygen and sulfate groups were preferentially removed. Detailed electrochemical and economic investigations suggest that the process operating at 85 °C achieves 95% silica removal (from an initial concentration of 481 mg L-1) with an electrical energy requirement of 0.52 kWh m-3, based on a charge loading of 1,200 C L-1, an inter-electrode gap of 1.8 cm and a current density of 16 mA cm-2.

Predicting successful sperm retrieval in transfeminine adolescents after testicular biopsy.

PURPOSE: Increasing numbers of transgender adolescents are receiving gender-affirming treatments (GAT). Given GAT can impair reproductive function, clinical guidelines advise prior counselling regarding fertility preservation (FP). For transgender adults assigned male at birth, FP is usually achieved via a masturbatory sample and sperm cryopreservation. This is less straightforward in transgender adolescents, since they may not be developmentally ready to masturbate and/or masturbation may cause unacceptable gender dysphoria. Testicular biopsy represents an alternative method for sperm retrieval in these adolescents, but for those in early/mid puberty, it is difficult to predict whether sperm will be found. The purpose of this study was therefore to identify factors that predict successful sperm retrieval for cryopreservation via testicular biopsy. METHODS: A retrospective cohort study was undertaken at a tertiary-referral pediatric gender service. Subjects were included if they'd received a testicular biopsy in association with the commencement of GAT between 2010 and 2019. The primary outcome measure was successful sperm retrieval, and potential predictors included age, testicular volume and serum testosterone, LH and FSH levels. RESULTS: Of 25 subjects who received a biopsy prior to starting any GAT, 17 had successful sperm retrieval. While age, testosterone, LH and FSH levels showed minimal differences, testicular volume was significantly higher in those with successful sperm retrieval, and a threshold of ≥ 10 mL showed 92% sensitivity and 71% specificity in predicting successful retrieval. An additional 6 patients received a biopsy after starting puberty suppression and before commencement of oestrogen, and one of these individuals had sperm successfully retrieved despite > 2 years of regular puberty suppression. CONCLUSION: These findings suggest that testicular volume is most useful in predicting successful sperm retrieval following testicular biopsy in transgender adolescents and are likely to be of relevance to other young people undertaking FP, including those with cancer.

A Systematic Review of Intra-abdominal Tissue Expansion for the Treatment of Exomphalos Major and a Case Report Describing a Refinement of the Technique.

ABSTRACT: The management of complex exomphalos major is difficult, and traditional techniques fail to address the visceroabdominal disproportion in the most severe cases. Intra-abdominal tissue expansion is a novel technique and has been used in a small number of patients to safely increase the intra-abdominal volume and allow the reduction of viscera and subsequent closure of the abdominal domain. We review 7 published reports of this technique and add a case report describing our refinement of the technique. We propose that the use of multiple expanders placed in the intra-abdominal preperitoneal space, when expanded slowly, can allow safe reduction of viscera and immediate direct closure of the musculofascial layer of the abdomen.

H-type congenital tracheoesophageal fistula: Insights from 70 years of The Royal Children's Hospital experience.

BACKGROUND: The long-term outcomes of H-type tracheoesophageal fistula (TOF), an uncommon variant of esophageal atresia/tracheoesophageal fistula (OA/TOF), are rarely described in the literature. We reviewed our institutional experience of 70 years. METHODS: The Nate Myers Oesophageal Atresia Database was queried for patients with an H-type TOF (1948-2017). Data included presentation, diagnostic workup, surgical management, and outcomes. RESULTS: Of 1088 patients with OA/TOF, 56 (5.1%) had an H-type TOF. The most common presenting symptoms were cyanotic episodes (68%), choking with feeds (52%), and aspiration pneumonitis (46%). The majority (82%) were symptomatic in the first week of life. Coexisting congenital anomalies were present in 46%: cardiac (13/56, 23%), genitourinary (10/56, 18%), and vertebral/skeletal (9/56, 16%). Patients were consistently diagnosed with prone contrast tube esophagogram (77% sensitivity on the first study and 96% after a second study). The fistula was most commonly approached through a right cervical collar incision. Right vocal cord palsy occurred in 22%, with one case of bilateral palsies. Other complications included leak (5.6%), recurrence (9.3%), stricture (1.9%), and diverticulum (1.9%). Although there was a trend towards a lower recurrence rate when interposition material was used, this was not statistically significant (3.3% vs 16.7%, p = 0.16). Survival in operative cases was 98.2%, and when all diagnosed cases were considered was 89.3%. CONCLUSIONS: We have reported the largest single-center series of H-type TOF. Diagnosis is challenging, and surgical morbidity remains high. Despite this, long-term outcomes are favorable. LEVEL OF EVIDENCE: IV.

Minimally invasive surgery for unilateral Wilms tumors: Multicenter retrospective analysis of 50 transperitoneal laparoscopic total nephrectomies.

PURPOSE: To evaluate feasibility and outcomes of minimally invasive surgery (MIS) in Wilms tumor (WT). METHODS: International multicenter review of MIS total nephrectomies for WT between 2006 and 2018. Medical records of confirmed WT were retrospectively assessed for demographic, imaging, treatment, pathology, and oncological outcome data. RESULTS: Fifty patients, with a median age of 38 months (6-181), were included in 10 centers. All patients received neoadjuvant chemotherapy, as per SIOP protocol. Median tumor volume post-chemotherapy was 673 mL (18-3331), 16 tumors crossed the lateral border of the spine, and three crossed the midline. Six patients with tumors that crossed the lateral border of the spine (tumor volumes 1560 mL [299-2480]) were converted to an open approach. There was no intraoperative tumor rupture. Overall, MIS was completed in 19% of the 195 nephrectomies for WT presenting during the study period. Tumor was stage I in 29, II in 16, and III in 5, and histology was reported as low in three, intermediate in 42, and high risk in five. Three patients had positive tumor margins. After a median follow-up of 34 months (2-138), there were two local recurrences (both stage I, intermediate risk, 7 and 9 months after surgery) and one metastatic relapse (stage III, high risk, four months after surgery). The three-year event-free survival was 94%. CONCLUSION: MIS is feasible in 20% of WT, with oncological outcomes comparable with open surgery, no intraoperative rupture, and a low rate of local relapse. Ongoing surveillance is, however, needed to evaluate this technique as it becomes widespread.

Methane oxidation and methylotroph population dynamics in groundwater mesocosms.

Extraction of natural gas from unconventional hydrocarbon reservoirs by hydraulic fracturing raises concerns about methane migration into groundwater. Microbial methane oxidation can be a significant methane sink. Here, we inoculated replicated, sand-packed, continuous mesocosms with groundwater from a field methane release experiment. The mesocosms experienced thirty-five weeks of dynamic methane, oxygen and nitrate concentrations. We determined concentrations and stable isotope signatures of methane, carbon dioxide and nitrate and monitored microbial community composition of suspended and attached biomass. Methane oxidation was strictly dependent on oxygen availability and led to enrichment of 13 C in residual methane. Nitrate did not enhance methane oxidation under oxygen limitation. Methylotrophs persisted for weeks in the absence of methane, making them a powerful marker for active as well as past methane leaks. Thirty-nine distinct populations of methylotrophic bacteria were observed. Methylotrophs mainly occurred attached to sediment particles. Abundances of methanotrophs and other methylotrophs were roughly similar across all samples, pointing at transfer of metabolites from the former to the latter. Two populations of Gracilibacteria (Candidate Phyla Radiation) displayed successive blooms, potentially triggered by a period of methane famine. This study will guide interpretation of future field studies and provides increased understanding of methylotroph ecophysiology.

A Probabilistic Approach for Predicting Methane Occurrence in Groundwater.

Aqueous geochemistry datasets from regional groundwater monitoring programs can be a major asset for environmental baseline assessment (EBA) in regions with development of natural gases from unconventional hydrocarbon resources. However, they usually do not include crucial parameters for EBA in areas of shale gas development such as methane concentrations. A logistic regression (LR) model was developed to predict the probability of methane occurrence in aquifers in Alberta (Canada). The model was calibrated and tested using geochemistry data including methane concentrations from two groundwater monitoring programs. The LR model correctly predicts methane occurrence in 89.8% (n = 234 samples) and 88.1% (n = 532 samples) of groundwater samples from each monitoring program. Methane concentrations strongly depend on the occurrence of electron donors such as sulfate and to a lesser extent on well depth and the total dissolved solids of groundwater. The model was then applied to a province-wide public health groundwater monitoring program (n = 52,849 samples) providing aqueous geochemistry data but no methane concentrations. This approach allowed the prediction of methane occurrence in regions where no groundwater gas data are available, thereby increasing the resolution of EBA in areas of shale gas development by using basic hydrochemical parameters measured in high-density groundwater monitoring programs.

Direct capture and conversion of CO2 from air by growing a cyanobacterial consortium at pH up to 11.2.

Bioenergy with carbon capture and storage (BECCS) is recognized as a potential negative emission technology, needed to keep global warming within safe limits. With current technologies, large-scale implementation of BECCS would compromise food production. Bioenergy derived from phototrophic microorganisms, with direct capture of CO2 from air, could overcome this challenge and become a sustainable way to realize BECCS. Here we present an alkaline capture and conversion system that combines high atmospheric CO2 transfer rates with high and robust phototrophic biomass productivity (15.2 ± 1.0 g/m 2 /d). The system is based on a cyanobacterial consortium, that grows at high alkalinity (0.5 mol/L) and a pH swing between 10.4 and 11.2 during growth and harvest cycles.

Wilms Tumor Associated With the 9q22.3 Microdeletion Syndrome: 2 New Case Reports and a Review of The Literature.

BACKGROUND: The 9q22.3 syndrome is an autosomal dominant microdeletion syndrome with similarities to Gorlin syndrome (GS). It encompasses the PTCH1 gene locus that harbors mutations for GS. Although the 9q22.3 syndrome is associated with Wilms tumor (WT), WT is not a GS-associated tumor, implying a different mechanism involving PTCH1, or a different locus in the 9q22.3 region. The goal of this study is to report the association between WT and 9q22.3 syndrome and review the outcome of treatment. OBSERVATIONS: We report 2 new cases of WT with 9q22.3 deletion and review the literature. Among the 44 described patients with 9q22.3 deletion, 7 developed WT (16%) at a mean age of 45 months (range, 4 to 84 mo). All patients had dysmorphic features, macrocephaly, and developmental delay, and there was an association with overgrowth (4/7). One patient had bilateral WT, another had a synchronous rhabdomyosarcoma. The outcome was excellent with all cases reported to be in complete remission. CONCLUSIONS: The 9q22.3 microdeletion syndrome should be considered at diagnosis of WT in children with dysmorphic features. Conversely, patients with a known 9q22.3 deletion syndrome should be considered for a WT predisposition surveillance program, especially those with overgrowth. The management should be individualized and given the excellent prognosis, and the unknown future risk of metachronous disease or other malignancy, the surgical approach should be carefully considered.

What is the risk of local recurrence after laparoscopic transperitoneal radical nephrectomy in children with Wilms tumours? Analysis of a local series and review of the literature.

BACKGROUND: To reduce long-term morbidity (adhesions-related complications and impaired quality of life due to scars), laparoscopy has been used as an alternative to open surgery in Wilms tumours (WTs). However, concerns have been raised on the risk of local recurrence after this type of resection. OBJECTIVE: The aim was to determine the incidence of local recurrence after laparoscopic transperitoneal radical nephrectomy (LTRN). STUDY DESIGN: We analysed 18 local cases and conducted a review of the English literature in Pubmed from 2004 to 2017 with the following keywords: (Wilms OR nephroblastoma) AND (laparoscopy OR minimally invasive surgery) AND 2004:3000. The review was conducted according to PRISMA guidelines. Data were collected independently in duplicate in a preformed Excel database. Review articles and duplicated case reports were excluded. Patients with retroperitoneoscopic or nephron-sparing surgery were also excluded. RESULTS: One hundred and four LTRNs have been performed for WT with neoadjuvant chemotherapy in 93 cases. Tumour was ruptured preoperatively in three cases but never intraoperatively. The median volume of the tumour was 229.4 mL (3.8-776 mL). Local stage was specified in 86 cases: 49 stage I, 28 stage II, and nine stage III. Lymph nodes were sampled in 48 patients (median 2.3 [0-14] nodes). Histology was reported in 90 cases: 27 favourable and two unfavourable histology (COG); and six low, 50 intermediate, and five high-risk tumours (International Society of Paediatric Oncology). With a median follow-up of 20.5 months (1-114 months), there were four local recurrences (3.8%) at a median of 8.5 (7-9) months after surgery. Three tumours were initial local stage I (2 intermediate and 1 high risk) and one stage III. The results are presented in the Figure. DISCUSSION: The incidence of local recurrence after LTRN is 3.8%. This is lower than previously reported after open resection. However, tumours amenable to minimally invasive surgery are smaller, with higher numbers of low stage and standard histology. Additionally, the quality of the reports is suboptimal and follow-up is relatively short. CONCLUSION: LTRN does not seem to increase the incidence of local recurrence in WT but inclusion of patients in international protocols with prolonged and systematic follow-up is of utmost importance to carefully evaluate this risk.

Laparoscopic nephrectomy for Wilms' tumor: Can we expand on the current SIOP criteria?

INTRODUCTION: Wilms' tumor now has a good overall prognosis with open radical nephrectomy having been the mainstay of surgical treatment. Recently laparoscopic nephrectomy (LN) has been growing in popularity. The aim of our study was to review our indications and outcomes for laparoscopic resections for Wilms' tumor and compare indications with International Society of Paediatric Oncology (SIOP) criteria for LN. MATERIAL AND METHODS: Patient demographics, preoperative management, surgical data, respect of SIOP criteria, complications, disease outcome, and follow-up were recorded on consecutive children who underwent nephrectomy for Wilms' tumor. RESULTS AND DISCUSSION: Fifty-four consecutive children with Wilms' tumor underwent a nephrectomy; 20 had a LN (Table). Nine of 20 (45%) patients who had LN did not meet SIOP criteria for LN. No patients had an intraoperative tumor rupture and one patient had positive margins because of preoperative rupture. There were two conversions: one caused by difficulty accessing the renal hilum and the other caused by difficulty maintaining oxygen saturations. There was one local recurrence. CONCLUSION: SIOP criteria are conservative and safe. Indications can be extended for teams experienced in surgical oncology and laparoscopy after agreement at a multidisciplinary meeting (MDM).

Midline cervical swellings: What a paediatrician needs to know.

Midline cervical swellings are a heterogeneous group of conditions in children. Careful clinical examination will allow a diagnosis to be made in many instances and appropriate investigations to be performed before referral to surgical services. The approach to clinical examination, investigation and management of the most common conditions is described.

Long-gap oesophageal atresia: comparison of delayed primary anastomosis and oesophageal replacement with gastric tube.

BACKGROUND: Long-gap oesophageal atresia (LGOA) causes significant early and long-term morbidity. We conducted a retrospective 25-year review comparing outcomes of delayed primary anastomosis versus oesophageal replacement with greater curvature gastric tube. METHODS: Records of 44 consecutive patients undergoing LGOA repair (1986-2010) were obtained from OA database with ethics approval and were analysed for complication and long-term outcomes. Analysis was conducted using Student's t-test for quantitative and Fisher exact test for qualitative data. RESULTS: Thirty (68%) patients underwent delayed primary anastomosis and 14 (32%) had oesophageal replacement. Oesophageal replacement patients had longer gaps (mean 5.5 vertebrae, range 4-9) compared to delayed primary anastomosis (mean 3.9, range 2-6) (p=0.004), but no difference in perioperative complications (p=0.2) (Table 1). Oesophageal replacement had more long-term complications (86%) compared to delayed primary anastomosis (30%) (p=0.005). Almost all patients (>90%) experienced gastro-oesophageal reflux and 21 delayed primary anastomosis patients (70%) underwent fundoplication. 60% of delayed primary anastomosis and 64.3% of oesophageal replacement patients had continued gastrointestinal symptoms years after repair. CONCLUSIONS: Our experience indicates that LGOA can be repaired safely using both methods, with no deaths and similar perioperative risk, but high long-term morbidity mandates long-term follow-up of these patients. Delayed primary anastomosis has a better long-term outcome compared to oesophageal replacement with gastric tube.

Successful subcutaneous glucagon use for persistent hypoglycaemia in congenital hyperinsulinism.

Abstract Congenital hyperinsulinism (CHI) results from inappropriate excessive insulin secretion by the beta cells in the pancreas. A wide clinical spectrum of disease exists and a genetic diagnosis is now possible for approximately 50% of affected children. We describe a patient with atypical diffuse CHI caused by mosaic ABCC8 mutation inheritance, unmasked by paternal uniparental disomy. Hypoglycaemia persisted despite two subtotal pancreatectomies and trials of diazoxide and nifedipine were unsuccessful. Octreotide resulted in anaphylaxis, precluding its use. Continuous subcutaneous glucagon infusion was successful in restoring normoglycaemia and attenuating weight gain, with concomitant improvement of developmental milestones. No adverse effects have been encountered after >12 months of therapy. Administration problems (e.g., line crystallisation) may complicate continuous glucagon therapy; hence a practical description of infusion constitution is included. We recommend consideration of continuous subcutaneous glucagon infusion as a therapeutic option for persistent refractory hypoglycaemia in CHI.

Identifying sources and processes controlling the sulphur cycle in the Canyon Creek watershed, Alberta, Canada.

Sources and processes affecting the sulphur cycle in the Canyon Creek watershed in Alberta (Canada) were investigated. The catchment is important for water supply and recreational activities and is also a source of oil and natural gas. Water was collected from 10 locations along an 8 km stretch of Canyon Creek including three so-called sulphur pools, followed by the chemical and isotopic analyses on water and its major dissolved species. The δ(2)H and δ(18)O values of the water plotted near the regional meteoric water line, indicating a meteoric origin of the water and no contribution from deeper formation waters. Calcium, magnesium and bicarbonate were the dominant ions in the upstream portion of the watershed, whereas sulphate was the dominant anion in the water from the three sulphur pools. The isotopic composition of sulphate (δ(34)S and δ(18)O) revealed three major sulphate sources with distinct isotopic compositions throughout the catchment: (1) a combination of sulphate from soils and sulphide oxidation in the bedrock in the upper reaches of Canyon Creek; (2) sulphide oxidation in pyrite-rich shales in the lower reaches of Canyon Creek and (3) dissolution of Devonian anhydrite constituting the major sulphate source for the three sulphur pools in the central portion of the watershed. The presence of H(2)S in the sulphur pools with δ(34)S values ∼30 ‰ lower than those of sulphate further indicated the occurrence of bacterial (dissimilatory) sulphate reduction. This case study reveals that δ(34)S values of surface water systems can vary by more than 20 ‰ over short geographic distances and that isotope analyses are an effective tool to identify sources and processes that govern the sulphur cycle in watersheds.

The use of ion exchange membranes for isotope analyses on soil water sulfate: laboratory experiments.

To investigate the potential use of anion exchange membranes (plant root simulator [PRS] probes) for isotope investigations of the soil sulfur cycle, laboratory experiments were performed to examine the sulfate exchange characteristics and to determine the extent of sulfur and oxygen isotope fractionation during sulfate sorption and desorption on the probes in aqueous solutions and simulated soil solutions. The sulfate-exchange tests in aqueous solutions under varying experimental conditions indicated that the amount of sulfate exchanged onto PRS probes increased with increasing reaction time, initial sulfate concentration, and the number of probes used (= surface area), whereas the percentage of removal of available sulfate was constant irrespective of the initial sulfate concentration. The competition of nitrate and chloride in the solution lowered the amount of exchanged sulfate. The exchange experiments in a simulated soil under water-saturated and water-unsaturated conditions showed that a considerable proportion of the soil sulfate was exchanged by the PRS probes after about 10 d. There was no evidence for significant sulfur and oxygen isotope fractionation between soil sulfate and sulfate recovered from the PRS probes. Therefore, we recommend the use of PRS probes as an efficient and easy way to collect soil water sulfate for determination of its isotope composition.

Aortic aneurysm repair in a peripheral setting: audit 100 consecutive cases.

BACKGROUND: Subspecialization of vascular surgery and the advent of endovascular techniques for aortic aneurysm repair have had a large impact on the approach to aortic surgery in main centres. Centralization of vascular surgery has been proposed to lower mortality and morbidity rates. More recently, clinical governance standards have been set by professional bodies for acceptable adverse outcome rates in aortic surgery. A peripheral general surgeon's experience with aortic surgery is reviewed in the present report in order to identify the local adverse outcome rates, and to relate them to case data and governance recommendations. METHODS: A retrospective audit of 100 cases of elective and emergency aortic aneurysm repair (performed by the senior author over a 10-year period) was undergone for the present review. Demographic and outcome data were recorded, and a data analysis was performed to identify factors related to mortality. Significance was tested using chi-squared analysis. RESULTS: Postoperative mortality rates were 1.7% for elective cases and 21% for acute cases. Mortality was related to rupture of the aneurysm, blood loss and American Society of Anesthetists score > 3. CONCLUSION: Morbidity and mortality rates from this audit compare favourably with those from larger vascular units. They are well within the accepted clinical governance rates, although the latter do not account for any case mix variation which may exist between peripheral and tertiary referral centres. These results support the continuation of aortic aneurysm surgery in peripheral centres.