Emerging investigator series: thermodynamic and energy analysis of nitrogen and phosphorous recovery from wastewaters

In a circular nutrient economy, nitrogen and phosphorous are removed from waste streams and captured as valuable fertilizer products, to more sustainably reuse the resources in closed-loops and simultaneously protect receiving aquatic environments from harmful N and P emissions. For nutrient reclamation to be competitive with the existing practices of N fixation and P mining, the methods of recovery must achieve at least comparable energy consumption. This study employed the Gibbs free energy of separation to quantify the minimum energy required to recover various N and P fertilizer products from waste streams of fresh and hydrolyzed urine, greywater, domestic wastewater, and secondary treated wastewater effluent. The comparative advantages in theoretical energy intensities for N and P recovery from nutrient-dense waste streams, such as fresh and hydrolyzed urine, were assessed against the other more dilute sources. For example, compared to reclaiming the nutrients from treated wastewater effluent at centralized wastewater treatment plants, the minimum energy required to recover 1.0 M NH3(aq) from source-separated hydrolyzed urine can be ≈40–68% lower, whereas recovering KH2PO4(s) from diverted fresh urine can, in principle, be ≈13–34% less energy intensive. The study also evaluated the efficiencies required by separation techniques for the energy demand of N and P recovery to be lower than the current production approaches of the Haber–Bosch process and phosphate rock mining. For instance, the most energetically favorable ammoniacal nitrogen and orthophosphate reclamation schemes, which target hydrolyzed and fresh urine, respectively, require energy efficiencies >7% and >39%. This study highlights that strategic selection of waste stream and fertilizer product can enable the most expedient recovery of nutrients and realize a circular economy model for N and P management

Vibrio fischeri -derived outer membrane vesicles trigger host development: OMV deliver signals in the squid/vibrio symbiosis

Outer membrane vesicles (OMV) are critical elements in many host-cell/microbe interactions. Previous studies of the symbiotic association between Euprymna scolopes and Vibrio fischeri had shown that, within 12 h of colonizing crypts deep within the squid’s light organ, the symbionts trigger an irreversible program of tissue development in the host. Here, we report that OMV produced by V. fischeri are powerful contributors to this process. The first detectable host response to the OMV is an increased trafficking of macrophage-like cells called hemocytes into surface epithelial tissues. We showed that exposing the squid to other Vibrio species fails to induce this trafficking; however, addition of a high concentration of their OMV, which can diffuse into the crypts, does. We also provide evidence that tracheal cytotoxin (TCT) release by the symbionts, which can induce hemocyte trafficking, is not part of the OMV cargo, suggesting two distinct mechanisms to induce the same morphogenesis event. By manipulating the timing and localization of OMV signal delivery, we showed that hemocyte trafficking is fully induced only when V. fischeri, the sole species able to reach and grow in the crypts, succeeds in establishing a sustained colonization. Further, our data suggest that the host detection of OMV serves as a symbiotic checkpoint prior to inducing irreversible morphogenesis

Donnan dialysis for phosphate recovery from diverted urine

There is a critical need to shift from existing linear phosphorous management practices to a more sustainable circular P economy. Closing the nutrient loop can reduce our reliance on phosphate mining, which has well-documented environmental impacts, while simultaneously alleviating P pollution of aquatic environments from wastewater discharges that are not completely treated. The high orthophosphate, HxPO4(3-x)-, content in source-separated urine offers propitious opportunities for P recovery. This study examines the use of Donnan dialysis (DD), an ion-exchange membrane-based process, for the recovery of orthophosphates from fresh and hydrolyzed urine matrixes. HxPO4(3-x)- transport against an orthophosphate concentration gradient was demonstrated and orthophosphate recovery yields up to 93% were achieved. By adopting higher feed to receiver volume ratios, DD enriched orthophosphate in the product stream as high as ≈2.5 × the initial urine feed concentration. However, flux, selectivity, and yield of orthophosphate recovery were detrimentally impacted by the presence of SO42− and Cl− in fresh urine, and the large amount of HCO3− rendered hydrolyzed urine practically unsuitable for P recovery using DD. The detrimental effects of sulfate ions can be mitigated by utilizing a monovalent ion permselective membrane, improving selectivity for HxPO4(3-x)- transport over SO42− by 3.1 × relative to DD with a conventional membrane; but the enhancement was at the expense of reduced orthophosphate flux. Critically, widely available and low-cost/waste resources with sufficiently high Cl− content, such as seawater and waste water softening regenerant rinse, can be employed to improve the economic viability of orthophosphate recovery. This study shows the promising potential of DD for P recovery and enrichment from source-separated urine

Novel Isothermal Membrane Distillation with Acidic Collector for Selective and Energy-Efficient Recovery of Ammonia from Urine

The high concentration of ammonia in source-separated urine offers propitious opportunities for N recovery. Membrane distillation (MD) can recover volatile ammonia from hydrolyzed urine, but conventional operation suffers from the simultaneous permeation of water vapor that results in poor selectivity for ammonia transport and high energy demand. Here, we present a novel operation of MD—isothermal membrane distillation with acidic collector (IMD-AC)—to overcome the limitations of conventional MD. The innovative isothermal operation, i.e., same feed and collector temperatures, effectively suppressed water vapor permeation while maintaining ammonia vapor flux and, thus, significantly improved selectivity for ammonia transport. The acidic collector further enhanced ammonia vapor flux by an average of 46.5% compared to using a deionized water collector. Against a total ammoniacal nitrogen concentration gradient, i.e., uphill transport, ammonia recovery of ≈60% was attained, highlighting the prospect of the technology for high-yield recovery. Critically, IMD-AC achieved approximately 95% savings in vaporization energy consumption relative to conventional MD by practically eliminating the evaporation of water. The resultant energy requirement of ≈2.2 kWh/kg-N is less than the Haber-Bosch process for N fixation and N removal by nitrification-denitrification (8.9–19.3 and 2.3–6.5 kWh/kg-N, respectively). This study shows the promising potential of IMD-AC for the selective and energy-efficient recovery of ammonia from source-separated urine

The methodology for developing a prospective meta-analysis in the family planning community

<p>Abstract</p> <p>Background</p> <p>Prospective meta-analysis (PMA) is a collaborative research design in which individual sites perform randomized controlled trials (RCTs) and pool the data for meta-analysis. Members of the PMA collaboration agree upon specific research interventions and outcome measures, ideally before initiation but at least prior to any individual trial publishing results. This allows for uniform reporting of primary and secondary outcomes. With this approach, heterogeneity among trials contributing data for the final meta-analysis is minimized while each site maintains the freedom to design a specific trial. This paper describes the process of creating a PMA collaboration to evaluate the impact of misoprostol on ease of intrauterine device (IUD) insertion in nulliparous women.</p> <p>Methods</p> <p>After the principal investigator developed a preliminary PMA protocol, he identified potential collaborating investigators at other sites. One site already had a trial underway and another site was in the planning stages of a trial meeting PMA requirements. Investigators at six sites joined the PMA collaborative. Each site committed to enroll subjects to meet a pre-determined total sample size. A final common research plan and site responsibilities were developed and agreed upon through email and face-to-face meetings. Each site committed to contribute individual patient data to the PMA collaboration, and these data will be analyzed and prepared as a multi-site publication. Individual sites retain the ability to analyze and publish their site's independent findings.</p> <p>Results</p> <p>All six sites have obtained Institutional Review Board approval and each has obtained individual funding to meet the needs of that site's study. Sites have shared resources including study protocols and consents to decrease costs and improve study flow. This PMA protocol is registered with the Cochrane Collaboration and data will be analyzed according to Cochrane standards for meta-analysis.</p> <p>Conclusions</p> <p>PMA is a novel research method that improves meta-analysis by including several study sites, establishing uniform reporting of specific outcomes, and yet allowing some independence on the part of individual sites with respect to the conduct of research. The inclusion of several sites increases statistical power to address important clinical questions. Compared to multi-center trials, PMA methodology encourages collaboration, aids in the development of new investigators, decreases study costs, and decreases time to publication.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00613366">NCT00613366</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT00886834">NCT00886834</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01001897">NCT01001897</a>, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01147497">NCT01147497</a> and <a href="http://www.clinicaltrials.gov/ct2/show/NCT01307111">NCT01307111</a></p

Impact of the Resident Microbiota on the Nutritional Phenotype of Drosophila melanogaster

Background: Animals are chronically infected by benign and beneficial microorganisms that generally promote animal health through their effects on the nutrition, immune function and other physiological systems of the host. Insight into the host-microbial interactions can be obtained by comparing the traits of animals experimentally deprived of their microbiota and untreated animals. Drosophila melanogaster is an experimentally tractable system to study host-microbial interactions. Methodology/Principal Findings: The nutritional significance of the microbiota was investigated in D. melanogaster bearing unmanipulated microbiota, demonstrated by 454 sequencing of 16S rRNA amplicons to be dominated by the a-proteobacterium Acetobacter, and experimentally deprived of the microbiota by egg dechorionation (conventional and axenic flies, respectively). In axenic flies, larval development rate was depressed with no effect on adult size relative to conventional flies, indicating that the microbiota promotes larval growth rates. Female fecundity did not differ significantly between conventional and axenic flies, but axenic flies had significantly reduced metabolic rate and altered carbohydrate allocation, including elevated glucose levels. Conclusions/Significance: We have shown that elimination of the resident microbiota extends larval development and perturbs energy homeostasis and carbohydrate allocation patterns of of D. melanogaster. Our results indicate that th

Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution.

The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies

A multimodal cell census and atlas of the mammalian primary motor cortex

ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties

Tracking HIV Post-Exposure Prophylaxis using Syndromic Surveillance in NYC Emergency Departments

HIV post-exposure prophylaxis (PEP) prescriptions are not uniformly monitored in the United States. We developed a method to identify PEP-related visits in New York City emergency departments (EDs). Using ED data, we observed a threefold increase in PEP-related visits to NYC EDs from 2002-2013. 73% of PEP-related visits were among males, and 45% among adults ages 25-34 years. Incorporation of this method of PEP monitoring in the NYC syndromic surveillance system will be used to observe trends and inform HIV outreach efforts

Strategic adaptabilty and firm performance : an empirical study of the miles and show typology

The motivations behind this study are to gain a deeper understanding and further insights on the Miles and Snow typology as well as to determine the applicability of the typology to Singapore's context. The primary objective of the study is to analyse the relationship between the four strategic types (Prospector, Defender, Analyser and Reactor}, as proposed by Miles and Snow ( 1978}, and company performance. A mail survey was conducted among 330 companies drawn from various industries in Singapore. 65 companies responded to the survey. In classifying organisations into the four strategic types, two approaches were used - paragraph descriptions and eleven-item scale. Performance results were measured based on performance indicators like Return on Investment (ROI) and Market Share. Investment decisions were measured using two dimensions : Timing of Investment and Breadth of Investment. The environment was assessed by looking at the degree of volatility or rate of change in the industry which the organisation competed in. One of the main findings shows that the performance of organisations differ across strategic types with Analyser performing the best. It was also found that the Analyser strategy has the highest performance in stable environments. This implies that if companies were to be in a stable environment, an appropriate strategy to minimise risk and maximise opportunities for profits would be that of an Analyser. In addition, other findings also show that the Defender is most likely to change its strategy to an Analyser strategy. The underlying implication is that the dynamism of the environment may render the Defender strategy to be less viable over time. Hence, changing to an Analyser strategy may be the next logical move. Further analyses show that most organisations emphasise profitability as a key performance measure with Prospector, Analysers and Reactors ranking net profit to sales as the most important performance indicator. On the other hand, Defenders placed market share as the most important element. Finally, the investment behaviour of the four archetypes is found not to be consistent with Collis' (1990) classification as proposed by Gibbons and Prescott (1993). The study does not provide substantial evidence to support their views. Therefore, further studies are necessary to verify the relationship between the four archetypes and Collis' framework. Other further research suggested include measuring the importance of new product development relative to other more appropriate indicators as well as determining the applicability of the Miles and Snow typology in the Asian economies.BUSINES