Life cycle assessment and techno-economic analysis of nitrogen recovery by ammonia air-stripping from wastewater treatment

Wastewater treatment plants (WWTPs) with anaerobic digestion of biosolids produce an ammonia-rich sidestream out of which nitrogen can be recovered through air stripping. Recovered ammonia can be used to produce ammonium sulfate (AS) for agricultural use, enabling the circular return of nitrogen as fertilizer to the food system. We investigate the cost and life cycle environmental impact of recovering ammonia from the sidestream of WWTPs for conversion to AS and compare it to AS production from the Haber Bosch process. We perform life cycle assessment (LCA) to investigate the environmental impact of AS fertilizer production by air-stripping ammonia from WWTP sidestreams at varying sidestream nitrogen concentrations. Techno-economic analysis (TEA) is performed to assess the break-even selling price of sidestream AS production at a WWTP in the City of Philadelphia. Greenhouse gas emissions for air-stripping technology range between 0.2 and 0.5 kg CO₂e/kg AS, about six times lower than the hydrocarbon-based Haber-Bosch process, estimated at 2.5 kg CO₂e/kg AS. Further reduction of greenhouse gas emissions is feasible by replacing fossil-based energy use in air-stripping process (82-98 % of net energy demand) with renewable sources. Also, a significant reduction in mineral depletion and improvement in human and ecosystem health are observed for the air-stripping approach. Furthermore, the break-even selling price for installing sidestream-based AS production at the Philadelphia's WWTP, considering capital and operating costs, is estimated at $0.046/kg AS (100 %), which is 92 % lower than the 2014 estimate of AS's average selling price at farms in the United States. We conclude that even with varying ammonia concentrations and high sidestream volume, air-stripping technology offers an environmentally and economically favorable option for implementing nitrogen recovery and simultaneous production of AS at WWTPs.

A randomized controlled trial of pharmacist-led therapeutic carbohydrate and energy restriction in type 2 diabetes

Type 2 diabetes can be treated, and sometimes reversed, with dietary interventions; however, strategies to implement these interventions while addressing medication changes are lacking. We conducted a 12-week pragmatic, community-based parallel-group randomized controlled trial (ClinicalTrials.gov: NCT03181165) evaluating the effect of a low-carbohydrate (<50 g), energy-restricted diet (~850-1100 kcal/day; Pharm-TCR; n = 98) compared to treatment-as-usual (TAU; n = 90), delivered by community pharmacists, on glucose-lowering medication use, cardiometabolic health, and health-related quality of life. The Pharm-TCR intervention was effective in reducing the need for glucose-lowering medications through complete discontinuation of medications (35.7%; n = 35 vs. 0%; n = 0 in TAU; p < 0.0001) and reduced medication effect score compared to TAU. These reductions occurred concurrently with clinically meaningful improvements in hemoglobin A1C, anthropometrics, blood pressure, and triglycerides (all p < 0.0001). These data indicate community pharmacists are a viable and innovative option for implementing short-term nutritional interventions for people with type 2 diabetes, particularly when medication management is a safety concern.

Community pharmacists are accessible healthcare providers with expertise in medication management. Here the authors show that a low-carbohydrate, low-energy diet implemented by community pharmacists reduced diabetes medication use and improved glucose control in people with type 2 diabetes.

Pharmacist-led therapeutic carbohydrate restriction as a treatment strategy for type 2 diabetes: the Pharm-TCR randomized controlled trial protocol

Background

The current treatment paradigm for type 2 diabetes mellitus (T2D) typically involves use of multiple medications to lower glucose levels in hope of reducing long-term complications. However, such treatment does not necessarily address the underlying pathophysiology of the disease and very few patients achieve partial, complete, or prolonged remission of T2D after diagnosis. The therapeutic potential of nutrition has been highlighted recently based on results of clinical trials reporting remission of T2D with targeted dietary approaches. During the initial phase of such interventions that restrict carbohydrates and/or induce rapid weight loss, hypoglycemia presents a notable risk to patients. We therefore hypothesized that delivering very low-carbohydrate, low-calorie therapeutic nutrition through community pharmacies would be an innovative strategy to facilitate lowering of glycated hemoglobin (A1C) while safely reducing the use of glucose-lowering medications in T2D.

Methods

A community-based randomized controlled trial that is pragmatic in nature, following a parallel-group design will be conducted (N = 200). Participants will have an equal chance of being randomized to either a pharmacist-led, therapeutic carbohydrate restricted (Pharm-TCR) diet or guideline-based treatment as usual (TAU). Pharm-TCR involves a 12-week very low carbohydrate, calorie-restricted commercial diet plan led by pharmacists and lifestyle coaches with pharmacists responsible for managing medications in collaboration with the participants’ family physicians. Main inclusion criteria are diagnosis of T2D, currently treated with glucose-lowering medications, age 30–75 years, and body mass index ≥ 30. The primary outcome is a binary measure of use of glucose-lowering medication. Secondary outcomes include A1C, anthropometrics and clinical blood markers.

Discussion

There are inherent risks involved if patients with T2D who take glucose-lowering medications follow very low carbohydrate diets. This randomized controlled trial aims to determine whether engaging community pharmacists is a safe and effective way to deliver therapeutic carbohydrate restriction and reduce/eliminate the need for glucose-lowering medications in people with T2D.

Trial registration

ClinicalTrials.gov, NCT03181165. Registered on 8 June 2017.

Timing of Atlantic salmon Salmo salar smolt migration predicts successful passage through a reservoir

Around 30% of Atlantic salmon Salmo salar smolts successfully survived passage through Loch Meig, a reservoir in the north of Scotland, en route to the sea. However, this survival rate was in turn dependent on the timing of migration, with the earliest migrants in the spring having the best chance of survival. This could have implication for fisheries management, since the estimation of smolt downstream survival may be influenced by which time period of the smolt run is analysed.

A comprehensive analysis of the human placenta transcriptome

As the conduit for nutrients and growth signals, the placenta is critical to establishing an environment sufficient for fetal growth and development. To better understand the mechanisms regulating placental development and gene expression, we characterized the transcriptome of term placenta from 20 healthy women with uncomplicated pregnancies using RNA-seq. To identify genes that were highly expressed and unique to the placenta we compared placental RNA-seq data to data from 7 other tissues (adipose, breast, hear, kidney, liver, lung, and smooth muscle) and identified several genes novel to placental biology (QSOX1, DLG5, and SEMA7A). Semi-quantitative RT-PCR confirmed the RNA-seq results and immunohistochemistry indicated these proteins were highly expressed in the placental syncytium. Additionally, we mined our RNA-seq data to map the relative expression of key developmental gene families (Fox, Sox, Gata, Tead, and Wnt) within the placenta. We identified FOXO4, GATA3, and WNT7A to be amongst the highest expressed members of these families. Overall, these findings provide a new reference for understanding of placental transcriptome and can aid in the identification of novel pathways regulating placenta physiology that may be dysregulated in placental disease.

Early maternal experience shapes offspring performance in the wild

Both the environments experienced by a mother as a juvenile and an adult can affect her investment in offspring. However, the implications of these maternal legacies, both juvenile and adult, for offspring fitness in natural populations are unclear. We investigated whether the juvenile growth rate and adult reproductive traits (length, body condition, and reproductive investment at spawning) of female wild Atlantic salmon (Salmo salar) were related to the growth and survival of their offspring. Adult salmon captured on their upstream migration were used to create experimental full-sib clutches of eggs, which were mixed and then placed in artificial nests in a natural stream that lacked salmon due to a migration barrier. Four months later we resampled the stream to obtain family-level estimates of offspring size and survival. Mothers that had grown slowly as juveniles (as determined by scalimetry) but had invested heavily in reproduction (egg production for a given body length) and were in relatively poor body condition (somatic mass for a given body length) at spawning produced the largest eggs. Larger eggs resulted in larger juveniles and higher juvenile survival. However, after controlling for egg size, offspring growth was positively related to maternal juvenile growth rate and reproductive investment. The predictors of offspring survival (i.e., reproductive success) varied with the juvenile growth rate of the mother: If females grew slowly as juveniles, their reproductive success was negatively related to their own body condition. In contrast, the reproductive success of females that grew quickly as juveniles was instead related positively to their own body condition. Our results show that maternal influences on offspring in the wild can be complex, with reproductive success related to the early life performance of the mother, as well as her state at the time of breeding.

Deposition of Atlantic salmon Salmo salar carcasses in a Scottish upland catchment

Radio telemetry was utilized to track 38 Atlantic salmon Salmo salar across space and time during and following their spawning run on the Conon system, Scotland. The data collected were used to assess the proportion of S. salar able to migrate successfully from an upland oligotrophic area of the catchment and the distribution of the carcasses of those fish that remained. Of these fish, 35% successfully migrated from the study area after the spawning period. The fish that remained were distributed approximately equally between riverine and lacustrine areas, but with a strong tendency to accumulate in regions of relatively slow water flows.

A hypothesis for the molecular mechanism of tumor killing by porphyrins and light

Tumor cells have an absence or deficiency of mitochondrial superoxide dismutase. Superoxide is produced when hematoporphyrin derivative is exposed to visible light. A significant portion of the antitumor effect of porphyrin:light therapy is hypothesized to be mediated by superoxide.