Aboriginal community-controlled art centres: Keeping Elders strong and connected. Articulating an ontologically situated, intergenerational model of care.

OBJECTIVE: To articulate how Aboriginal community-controlled art centres support the role of Elders and older people within an ontologically situated, intergenerational model of care. METHODS: In this paper, we draw on stories (data) generated through interviews involving 75 people associated with three Aboriginal community-controlled art centres and field notes taken during a Participatory Action Research (PAR) study. The study was undertaken in collaboration with three community-controlled art centres and two aged care providers over almost 4 years, in diverse Indigenous sovereignties, all located in geographically remote Australian locations. RESULTS: Engaging with decolonising and Indigenous theoretical frameworks, our analysis identified three interwoven meta-themes. These include connection to law and culture; purpose; and healing. Each theme had important subthemes, and all were central to upholding the well-being of older people and their families, as well as the art centre workforce, Country, and their broader communities. CONCLUSIONS: Our analysis articulates an ontologically situated model of care within Aboriginal community-controlled art centres. The model sees that older people receive care from art centres and provide care to each other, to younger generations, to art centre staff, to Country, and to their broader communities. In this model, those in receipt of care, many of whom are older people, art centre directors, and important artists, govern how care is conceptualised and delivered.

Mid-regional proadrenomedullin (MR-proADM), C-reactive protein (CRP) and other biomarkers in the early identification of disease progression in patients with COVID-19 in the acute NHS setting.

AIMS: There is a lack of biomarkers validated for assessing clinical deterioration in patients with COVID-19 on presentation to secondary or tertiary care. This evaluation looked at the potential clinical application of C reactive protein (CRP), procalcitonin, mid-regional proadrenomedullin (MR-proADM) and white cell count to support prediction of clinical outcomes. METHODS: 135 patients presenting to Hampshire Hospitals NHS Foundation Trust between April and June 2020 confirmed to have COVID-19 via reverse-transcription-qPCR were included. Biomarkers from within 24 hours of presentation were used to predict disease progression by Cox regression and area under the receiver operating characteristic curves. The endpoints assessed were 30-day all-cause mortality, intubation and ventilation, critical care admission and non-invasive ventilation (NIV) use. RESULTS: Elevated MR-proADM was shown to have the greatest ability to predict 30-day mortality adjusting for age, cardiovascular disease, renal disease and neurological disease. A significant association was also noted between raised MR-proADM and CRP concentrations and the requirement for critical care admission and NIV. CONCLUSIONS: The measurement of MR-proADM and CRP in patients with confirmed COVID-19 infection on admission shows significant potential to support clinicians in identifying those at increased risk of disease progression and need for higher level care, subsequently enabling prompt escalation in clinical interventions.

The association between self-efficacy on function and pain outcomes among patients with chronic low back pain managed using the McKenzie approach: a prospective cohort study.

INTRODUCTION: Self-efficacy is a determinant of function and pain outcomes in patients with chronic low back pain receiving physiotherapy. The McKenzie approach is an effective intervention for patients with back pain that may affect self-efficacy. Study aims were to determine if, among patients with back pain being managed by McKenzie-credentialed physiotherapists: intake self-efficacy is correlated with intake function and pain; intake self-efficacy is associated with changes in function and pain during treatment; self-efficacy improves during treatment; and improvements in self-efficacy during treatment are associated with improvements in function and pain at discharge. METHODS: Two-hundred-eighty-two subjects with chronic low back pain seen by McKenzie-credentialed clinicians provided data on self-efficacy, function and pain at intake and discharge. RESULTS: Self-efficacy was correlated with function and pain at intake; however, intake self-efficacy was not associated with function or pain outcomes. Self-efficacy increased during treatment. This increase was associated with improvements in function and pain at discharge. CONCLUSION: While intake self-efficacy was associated with function and pain when initiating physiotherapy, it did not result in improved treatment outcomes. Specific interventions may be necessary to improve self-efficacy. The increases in self-efficacy observed during treatment were associated with improvements in function and pain outcomes at discharge.

Thermodynamic Analysis of Intermediary Metabolic Steps and Nitrous Oxide Production by Ammonium-Oxidizing Bacteria.

Nitrous oxide (N2O) is a greenhouse gas emitted from wastewater treatment, soils, and agriculture largely by ammonium-oxidizing bacteria (AOB). While AOB are characterized by being aerobes that oxidize ammonium (NH4+) to nitrite (NO2-), fundamental studies in microbiology are revealing the importance of metabolic intermediates and reactions that can lead to the production of N2O. These findings about the metabolic pathways for AOB were integrated with thermodynamic electron-equivalents modeling (TEEM) to estimate kinetic and stoichiometric parameters for each of the AOB's nitrogen (N)-oxidation and -reduction reactions. The TEEM analysis shows that hydroxylamine (NH2OH) oxidation to nitroxyl (HNO) is the most energetically efficient means for the AOB to provide electrons for ammonium monooxygenation, while oxidations of HNO to nitric oxide (NO) and NO to NO2- are energetically favorable for respiration and biomass synthesis. The respiratory electron acceptor can be O2 or NO, and both have similar energetics. The TEEM-predicted value for biomass yield, maximum-specific rate of NH4+ utilization, and maximum specific growth rate are consistent with empirical observations. NO reduction to N2O is thermodynamically favorable for respiration and biomass synthesis, but the need for O2 as a reactant in ammonium monooxygenation likely precludes NO reduction to N2O from becoming the major pathway for respiration.

Thermophotovoltaic efficiency of 40.

Thermophotovoltaics (TPVs) convert predominantly infrared wavelength light to electricity via the photovoltaic effect, and can enable approaches to energy storage1,2 and conversion3-9 that use higher temperature heat sources than the turbines that are ubiquitous in electricity production today. Since the first demonstration of 29% efficient TPVs (Fig. 1a) using an integrated back surface reflector and a tungsten emitter at 2,000 °C (ref. 10), TPV fabrication and performance have improved11,12. However, despite predictions that TPV efficiencies can exceed 50% (refs. 11,13,14), the demonstrated efficiencies are still only as high as 32%, albeit at much lower temperatures below 1,300 °C (refs. 13-15). Here we report the fabrication and measurement of TPV cells with efficiencies of more than 40% and experimentally demonstrate the efficiency of high-bandgap tandem TPV cells. The TPV cells are two-junction devices comprising III-V materials with bandgaps between 1.0 and 1.4 eV that are optimized for emitter temperatures of 1,900-2,400 °C. The cells exploit the concept of band-edge spectral filtering to obtain high efficiency, using highly reflective back surface reflectors to reject unusable sub-bandgap radiation back to the emitter. A 1.4/1.2 eV device reached a maximum efficiency of (41.1 ± 1)% operating at a power density of 2.39 W cm-2 and an emitter temperature of 2,400 °C. A 1.2/1.0 eV device reached a maximum efficiency of (39.3 ± 1)% operating at a power density of 1.8 W cm-2 and an emitter temperature of 2,127 °C. These cells can be integrated into a TPV system for thermal energy grid storage to enable dispatchable renewable energy. This creates a pathway for thermal energy grid storage to reach sufficiently high efficiency and sufficiently low cost to enable decarbonization of the electricity grid.

Experiences of a community of research practice: a service evaluation.

BACKGROUND: A community of research practice (CRP) was established to increase research capacity and provide learning opportunities and networking for healthcare practitioners, working within a Children's Care Group. The CRP aimed to engage research-interested practitioners in research to develop their skills and confidence, encourage networking, and build research capacity. AIM: To report the results of a service evaluation that was undertaken to review the CRP's value in practice. DISCUSSION: Thematic analysis revealed four themes - 'positive environment', 'confidence', 'professional development' and 'networking' - highlighting benefits from the CRP, alongside the challenges encountered. CONCLUSION: This article highlights the significant contribution of CRP for practitioners in the context of an innovative organisation with a supportive culture. IMPLICATIONS FOR PRACTICE: A CRP empowers healthcare practitioners to engage with research while in clinical practice, enabling increased research confidence, and the development of research skill and knowledge and enhanced networking. CRP can potentially influence recruitment and retention.

A delirium prevalence audit and a pre and post evaluation of an interprofessional education intervention to increase staff knowledge about delirium in older adults.

BACKGROUND: Delirium is more prevalent in older people and estimated to occur in up to 50% of the hospital population. Delirium comprises a spectrum of behaviours, including cognitive and attention deficits, and fluctuating levels of consciousness, often associated with an underlying physiological disturbance. Delirium has been increasingly associated with adverse outcomes. Although often preventable or can at least be mitigated, delirium may not be a standard part of assessment and thus may not be recognized in the early stages when it is most likely to be treated successfully. The aim of this study was to evaluate the level of knowledge of delirium amongst clinicians caring for patients at high risk of developing delirium and to determine whether education can improve clinical assessment of delirium. METHODS: Two hundred and forty-six case notes were audited before and 149 were reviewed after the education intervention and implementation of a delirium screening tool. Clinicians at the hospital were invited to complete a questionnaire on knowledge of delirium. The questionnaire was based on a validated tool which contained 39 questions about delirium. The questionnaire also contained 28 questions on delirium knowledge. Additional questions were included to gather demographic information specific to the hospital. Descriptive statistics, chi square and independent t-tests were conducted to test for differences in knowledge between the pre and post periods. The Squire Checklist Reporting Guidelines for Quality Improvement Studies informed the preparation of the manuscript. RESULTS: The audit demonstrated that the use of a cognitive assessment tool overall increased from 8.5% in pre education to 43% in the post education period. One hundred and fifty-nine staff completed the questionnaire in total, 118 the pre and 41 post. The knowledge subscale score was high pre and post education and no statistically significant difference was observed. The greatest increase in knowledge was related to knowledge of the risk factors subscale. The increase in knowledge (6.8%) was statistically significant. CONCLUSION: An interprofessional approach to delirium education was effective in not only increasing awareness of the factors associated with this syndrome but also increased the use of a delirium assessment tool.

Participatory Development Process of Two Human Dimension Intervention Programs to Foster Physical Fitness and Psychological Health and Well-Being in Wildland Firefighting.

Intervention programs designed, delivered, and evaluated by and within organizations are a critical component in the promotion of employee health and well-being and in the prevention of occupational injury. Critical for transference of findings across complex occupational settings is a clearly articulated development process, a reliance on and evaluation of underlying theoretical foundations, and the inclusion of relevant outcomes emerging out of participatory action processes. To date, there have been no documented efforts outlining the development, implementation, or evaluation of human dimension intervention programs targeting wildland firefighters. The purpose of this paper is to outline the development of two collaborative and participatory intervention programs, targeting wildland firefighters' physical and psychological health and well-being. Two human dimension intervention programs were developed in a collaborative, iterative and participatory process following the Context-Content-Process-Outcomes Framework. First, a physical fitness training intervention program was designed to maintain wildland firefighter's physical fitness levels and attenuate risk of injury. Second, a psychosocial education intervention program was developed to mitigate the impact of psychosocial risk factors, foster work engagement, and decrease job stress. The current study provides evidence for the capacity of researchers and organizations to collaboratively develop practical programs primed for implementation and delivery.

Retrospective Quality Improvement Study of Insulin-Induced Hypoglycemia and Implementation of Hospital-Wide Initiatives.

BACKGROUND: Hospitalized patients who are receiving antihyperglycemic agents are at increased risk for hypoglycemia. Inpatient hypoglycemia may lead to increased risk for morbidity, mortality, prolonged hospitalization, and readmission within 30 days of discharge, which in turn may lead to increased costs. Hospital-wide initiatives targeting hypoglycemia are known to be beneficial; however, their impact on patient care and economic measures in community nonteaching hospitals are unknown. METHODS: This retrospective quality improvement study examined the effects of hospital-wide hypoglycemia initiatives on the rates of insulin-induced hypoglycemia in a community hospital setting from January 1, 2016, until September 30, 2019. The potential cost of care savings has been calculated. RESULTS: Among 49 315 total patient days, 2682 days had an instance of hypoglycemia (5.4%). Mean ± SD hypoglycemic patient days/month was 59.6 ± 16.0. The frequency of hypoglycemia significantly decreased from 7.5% in January 2016 to 3.9% in September 2019 (P = .001). Patients with type 2 diabetes demonstrated a significant decrease in the frequency of hypoglycemia (7.4%-3.8%; P < .0001), while among patients with type 1 diabetes the frequency trended downwards but did not reach statistical significance (18.5%-18.0%; P = 0.08). Based on the reduction of hypoglycemia rates, the hospital had an estimated cost of care savings of $98 635 during the study period. CONCLUSIONS: In a community hospital setting, implementation of hospital-wide initiatives targeting hypoglycemia resulted in a significant and sustainable decrease in the rate of insulin-induced hypoglycemia. These high-leverage risk reduction strategies may be translated into considerable cost savings and could be implemented at other community hospitals.

Ericoid mycorrhizal fungi enhance salt tolerance in ericaceous plants.

To examine the effects of ericoid mycorrhizal (ERM) fungi on salt tolerance of ericaceous plants, we inoculated roots of velvetleaf blueberry (Vaccinium myrtilloides), Labrador tea (Rhododendron groenlandicum), and lingonberry (Vaccinium vitis-idaea) with ericoid mycorrhizal fungi Oidiodendron maius and Meliniomyces variabilis. Plants were subjected to 0 (NaCl control) and 30 mM NaCl treatments, and plant dry weights, gas exchange, and leaf chlorophyll concentrations were compared in inoculated and non-inoculated plants. M. variabilis increased root dry weights in all three species of NaCl-treated plants, and O. maius enhanced root dry weights of lingonberry plants treated with NaCl. Both fungal species were especially effective in enhancing root and shoot dry weights in control (0 mM NaCl) and NaCl-treated lingonberry seedlings. Leaf chlorophyll concentrations were enhanced by fungal inoculation in all three plant species, and this effect persisted under salt stress in Labrador tea and lingonberry. Salt treatment drastically reduced transpiration rates (E) and lowered net photosynthesis (Pn) to the negative values in all three species of non-inoculated plants, and this effect was partly or almost completely reversed by the inoculation with O. maius and M. variabilis. Fungal inoculation was especially effective in reducing NaCl effects on Pn in lingonberry. Oidiodendron maius and M. variabilis were also equally effective in reversing NaCl-induced declines of E in velvetleaf blueberry and lingonberry. However, in Labrador tea, O. maius reversed the decline of E in NaCl-treated plants less compared with M. variabilis resulting in high photosynthetic water use efficiency values. The results support the hypothesis that, similarly to arbuscular mycorrhizal and ectomycorrhizal associations, ERM association increases salt tolerance of plants.

Association between changes in function among patients with lumbar impairments classified according to the STarT Back Screening Tool and managed by McKenzie credentialed physiotherapists.

PURPOSE: To examine the association between functional status (FS) scores using a Patient Reported Outcome Measure (PROM) for patients with non-specific low back pain classified according to psychosocial risk using the STarT Back Screening Tool and managed by physiotherapists credentialed in McKenzie methods. METHODS: Participants (n = 705) completed FS and STarT surveys at intake and discharge. Prevalence of STarT risk classifications and change in STarT risk was calculated. Regression models were developed to examine associations between baseline and change in STarT risk categories, and FS outcomes at discharge from rehabilitation services. RESULTS: FS outcomes at discharge was not significantly different (p-values > 0.10) across baseline STarT risk subgroups after controlling for model covariates. Seventy-eight and 91.5% of medium and high-risk patients respectively decreased STarT risk. When compared with subjects whose STarT risk decreased, there was no significant difference in subjects whose STarT risk remained low. For subjects whose risk remained medium/high, or whose risk worsened, FS outcome scores were statistically significant (p < 0.001) and clinically relevant (-15.76 and -23.42 points respectively) compared to patients whose STarT risk decreased. CONCLUSIONS: Baseline STarT psychosocial risk stratifications should be interpreted cautiously to estimate the likelihood of good or poor FS outcomes at discharge from physiotherapy practice in the US when patients are managed by clinicians credentialed in McKenzie methods. Decreased STarT risk was associated with clinically important improvements in FS outcomes scores at discharge from McKenzie directed physiotherapy care.

Cognitive behavioural interventions, and function and pain outcomes among patients with chronic neck pain managed with the McKenzie approach.

OBJECTIVES: Graded activity and graded exposure in vivo are recommended cognitive behavioural approaches to improve function and pain outcomes for patients receiving physiotherapy for chronic nonspecific neck pain. The McKenzie method is a common treatment approach for patients with neck pain. The study objectives were to examine associations between interventions with graded activity and/or graded exposure, as determined by the treating physiotherapist, and function and pain outcomes for patients with chronic nonspecific neck pain managed by clinicians with credentials in the McKenzie approach. METHOD: A cohort study was carried out, in which subjects (n = 366) with chronic nonspecific neck pain completed intake surveys (i.e., the Neck Functional Status Computerized Adaptive Test and the Numeric Pain Rating Scale), and questions related to their demographic, lifestyle and health status. Treatment with graded activity/graded exposure during the episode of care was recorded. Function and pain measures were repeated at discharge. Multivariable models examining associations between patients receiving versus not receiving graded activity/graded exposure, and pain and function outcomes were constructed, controlling for potential confounding effects. RESULTS: Despite statistical significance, there were no clinically relevant differences between treatment versus no treatment with graded activity/graded exposure, and function or pain outcomes. CONCLUSION: There is insufficient evidence to suggest that patients being managed with McKenzie methods will attain clinically relevant improvements in function or pain outcomes when augmenting treatment with graded activity and/or graded exposure when the choice to intervene with these cognitive behavioural approaches is determined by the treating physiotherapist.

Bilateral congenital radioulnar synostosis in an Early Horizon subadult burial from the site of Atalla, Peru.

OBJECTIVE: This study was undertaken to identify pathological conditions within the population living at Atalla (1000-500 BCE), an important early village site and ritual center located in Huancavelica, Peru. MATERIALS: Articulated burials (N = 3) and commingled human remains excavated during the 2015 and 2016 field seasons. METHODS: Osteological remains were analyzed for macroscopic evidence of pathological changes. RESULTS: A case of bilateral proximal radioulnar fusion was observed in an Early Horizon (ca. 800 BCE) subadult skeleton (Individual 1). A differential diagnosis of this pathology supports congenital radioulnar synostosis (CRUS), a rare developmental condition. Enamel hypoplasia was also identified in the same individual. CONCLUSIONS: Burial treatment of Individual 1 does not provide any indication that CRUS was afforded an exceptional social significance. CONTRIBUTION TO PALEOPATHOLOGY: This example of CRUS is notable as it represents the second published archaeological case of CRUS from Peru and the earliest reported case globally. LIMITATIONS OF THIS STUDY: The osteological sample currently available from this site is limited. SUGGESTIONS FOR FUTURE RESEARCH: Increased fieldwork in this region is recommended to further clarify the distribution and social significance of CRUS in the prehistoric Andes.

The Nutritional Value of Children's Menus in Chain Restaurants in the United Kingdom and Ireland.

OBJECTIVE: Obesity in the United Kingdom and the Republic of Ireland is rising, as is the frequency of eating out in restaurants. The aim of this study was to investigate the nutritional quality of children's menus in restaurants. DESIGN: Cross-sectional review of menus aimed at children from 20 popular chain restaurants in the United Kingdom and Ireland. MAIN OUTCOME MEASURES: Total energy, fat, saturated fat, and salt were collected from every food item on the menu in each restaurant. All potential meal combinations were created. A total of 39,266 meals were analysed. ANALYSIS: Meals were compared with UK nutritional guidelines. Meals from fast food and full-service restaurants and main meals and meal deals were compared. RESULTS: The average meal for younger children (aged 2-5 years) contained 609 ±117 kcal, and for older children (6-12 years) 653 ± 136 kcal compared with guidelines of 364 and 550 kcal, respectively. A total of 68% of younger children's and 55% of older children's meals contained more total fat than recommended and more than 4 times the amount of saturated fat. Fast food restaurant meals contained less energy, fat, and salt than did full-service restaurants, and meal deals were less likely to meet dietary guidelines than were main meals alone. CONCLUSION AND IMPLICATIONS: Eating in chain restaurants, in particular meal deals, does not contribute positively to the diet of children in the United Kingdom and Ireland.

Directional preference, cognitive behavioural interventions, and outcomes among patients with chronic low back pain.

OBJECTIVES: Graded activity and graded exposure are recommended cognitive behavioural approaches to improve function and pain outcomes for patients receiving physiotherapy for chronic nonspecific low back pain. Directional preference identified following the McKenzie method is also associated with favourable patient outcomes. Study objectives were to examine associations between graded activity and/or graded exposure, and directional preference or no directional preference combined with or without graded activity/graded exposure subgroups, and function and pain outcomes among patients with chronic nonspecific low back pain managed by clinicians credentialed in the McKenzie approach. METHOD: Cohort study: Subjects (n = 801) with chronic nonspecific low back pain completed intake surveys, that is, the Lumbar Computer Adaptive Test measuring function and the Numeric Pain Rating Scale measuring pain, and questions addressing their demographic, lifestyle, and health status. Directional preference was determined at intake. Treatment with graded activity/graded exposure during the episode of care was recorded. Function and pain measures were repeated at discharge. Two models were developed controlling for potential confounding effects. The first model examined associations between patients receiving versus not receiving graded activity/graded exposure. The second model examined interaction effects between four combinations of directional preference and graded activity/graded exposure. Outcome measures were changes in function and pain during rehabilitation. RESULTS: Regarding the first objective, there were no clinically relevant differences between treatment versus no treatment with graded activity/graded exposure, and functional outcomes. Regarding the second objective, patients in the no-directional preference group were more likely to see benefits from the addition of graded activity/graded exposure to their treatment groups than those with a directional preference. CONCLUSION: Clinicians using McKenzie methods might attain improved patient functional outcomes when augmenting treatment with graded activity and/or graded exposure among patients who do not demonstrate directional preference.

Directional preference and functional outcomes among subjects classified at high psychosocial risk using STarT.

BACKGROUND AND PURPOSE: Physiotherapy has an important role in managing patients with non-specific low back pain who experience elevated psychosocial distress or risk for chronic disability. In terms of evidence-based physiotherapy practice, cognitive-behavioural approaches for patients at high psychosocial risk are the recommended management to improve patient treatment outcomes. Evidence also suggests that directional preference (DP) is an important treatment effect modifier for prescribing specific exercises for patients to improve outcomes. Little is known about the influence of treatment techniques based on DP on outcomes for patients classified as high psychosocial risk using the Subgroups for Targeted Treatment (STarT) Back Screening Tool. This study aimed to examine the association between functional status (FS) at rehabilitation discharge for patients experiencing low back pain classified at high STarT psychosocial risk and whose symptoms showed a DP versus No-DP. METHODS: High STarT risk patients (n = 138) completed intake surveys, that is, the lumbar FS of Focus On Therapeutic Outcomes, Inc., and STarT, and were evaluated for DP by physiotherapists credentialed in McKenzie methods. The FS measure of Focus On Therapeutic Outcomes, Inc., was repeated at discharge. DP and No-DP prevalence rates were calculated. Associations between first-visit DP and No-DP and change in FS were assessed using univariate and multivariate regression models controlling for 11 risk-adjusted variables. RESULTS: One hundred nine patients classified as high STarT risk had complete intake and discharge FS and DP data. Prevalence rate for DP was 65.1%. A significant and clinically important difference (7.98 FS points; p = .03) in change in function at discharge between DP and No-DP was observed after controlling for all confounding variables in the final model. CONCLUSION: Findings suggest that interventions matched to DP are effective for managing high psychological risk patients and may provide physiotherapists with an alternative treatment pathway compared to managing similar patients with cognitive-behavioural approaches. Stricter research designs are required to validate study conclusions.

Enhancing anaerobic digestion of food waste through biochemical methane potential assays at different substrate: inoculum ratios.

Food waste has a high energy potential that can be converted into useful energy in the form of methane via anaerobic digestion. Biochemical Methane Potential assays (BMPs) were conducted to quantify the impacts on methane production of different ratios of food waste. Anaerobic digester sludge (ADS) was used as the inoculum, and BMPs were performed at food waste:inoculum ratios of 0.42, 1.42, and 3.0g chemical oxygen demand/g volatile solids (VS). The 1.42 ratio had the highest CH4-COD recovery: 90% of the initial total chemical oxygen demand (TCOD) was from food waste, followed by ratios 0.42 and 3.0 at 69% and 57%, respectively. Addition of food waste above 0.42 caused a lag time for CH4 production that increased with higher ratios, which highlighted the negative impacts of overloading with food waste. The Gompertz equation was able to represent the results well, and it gave lag times of 0, 3.6 and 30days and maximum methane productions of 370, 910, and 1950mL for ratios 0.42, 1.42 and 3.0, respectively. While ratio 3.0 endured a long lag phase and low VSS destruction, ratio 1.42 achieved satisfactory results for all performance criteria. These results provide practical guidance on food-waste-to-inoculum ratios that can lead to optimizing methanogenic yield.

Determining the Mechanism for Low Sludge Yields in the Cannibal Solids Reduction System.

Extracellular polymeric substances (EPS) and solids concentrations in samples from the Interchange Bioreactor (IBR), and return activated sludge (RAS) from Cannibal facilities having low and high sludge yields, were analyzed to understand the mechanisms behind low sludge production. Low sludge yields correlated to more EPS degradation, higher concentrations of iron, and reducing conditions in the IBR. In the low yield facilities, iron was reduced when the RAS passed through the anaerobic and reducing conditions of the IBR, and this led to more EPS solubilization and degradation. This "futile cycle" of EPS production and degradation appears to may have been most responsible for reducing sludge yields.