Factors Influencing Water Extractable Phosphorus Reduction in Poultry Litter by Chitosan Treatment

Phosphorus is known to be a chief factor in the eutrophication of freshwaters. Phosphorus in land applied poultry litter can runoff and pollute these freshwaters. Chitosan, the deacetylated form of the biopolymer chitin, has been shown to have an effect on reducing water extractable phosphorus (WEP) in poultry litter when applied as a powder. The intent of this study was to measure the effect that acetic acid and incubation time have on chitosan’s ability to reduce WEP in poultry litter. The results were that the presence of poultry litter treatment (PLT) in the litter inhibits chitosan’s ability reduce WEP. Chitosan dissolved in acetic acid does not decrease WEP after any amount of incubation time. Chitosan in a powder form reaches its full effectiveness after three weeks of incubation

Phosphorus buffering in streams by benthic sediments : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University

The loss of phosphorus (P) to aquatic ecosystems accelerates eutrophication – a problem felt worldwide. Central to any effort to monitor and mitigate the effect of P in stream is knowing how inputs of P, whether point or diffuse, map to P transport downstream. However, the stream itself possesses several mechanisms to attenuate P inputs thus blurring the connection between P inputs and P availability in-stream. For example, various stream biota and geochemical processes may remove P from or even release P to the water column. In particular, benthic stream sediments have the capacity to sorb P to their surfaces which may later desorb back into solution. This P sorption means benthic sediments can behave much like a buffer for P: a transient store of P which may offset changes to P concentrations in the stream. The thesis of this work is that the benthic sediment-P buffer is a predominant control on P availability at baseflow in streams. In its five studies, I investigate sediment-P sorption in detail but also examine multiple alternative pathways for stream P retention. Special attention is given to the sediment equilibrium phosphate concentration at net zero sorption (EPC0), which is the dissolved reactive P (DRP) concentration towards which sediments buffer DRP concentrations in the solution (i.e., sediment porewater and, via hyporheic exchange, the water column) through sorption. A systematic review and meta-analysis of the EPC0 in streams at baseflow – covering 45 studies and 466 stream sites across the globe – found wide variability in the disparity between in-stream DRP concentrations and sediment EPC0 (termed as a potential for P exchange). This contrasts with previous views that P in sediments and streamwater is typically in an ‘equilibrium’. Further, this potential for P exchange was moderated by sediment and stream characteristics, including sorption affinity, pH, and sediment exchangeable P concentrations. For example, fine benthic sediments are often highly sorptive but may also restrict hydrological exchange between the water column and the hyporheic zone, leading to wider disparities. Methodological factors were also influential (e.g., choice of solution, sediment pre-treatment, equilibration time), indicating a need for research on unified EPC0 methodology. The second study established that drying sediments prior to analyses (either air- or freeze-drying) biases sediment P fractionation measurements and inflates the variance of EPC0. Such drying techniques may lyse microbial biomass P, alter organic P availability, and age metal oxides responsible for sorption, thus complicating the natural sediment P chemistry. Instead, analyzing stream sediments fresh (wet) is recommended. The third study surveyed a variety of stream waters and sediments from catchments draining three distinct lithologies (alluvium, sedimentary, and volcanic basic) to assess the likelihood of various geochemical controls on stream DRP concentrations. Geochemical equilibria in the water-column indicated no significant potential for the (co-)precipitation of minerals that could sequester P (e.g., calcite). However, the sediments stored large amounts of P in labile and redox-sensitive forms: indeed, this labile P correlated with stream DRP concentrations but only for streams with likely sufficient hyporheic exchange. Catchment geology and redox cycling in stream influence sediment reactivity for P and so are a major source of between-stream variability in DRP concentrations. The fourth study focused on a confounding factor when interpreting EPC0: is P sorption or microbial P cycling responsible for sediment P buffering? Unlike some previous work, this study found a minimal role for sediment microbes to alter sediment EPC0 values even with replete labile carbon and nitrogen sources available. Further, sediments sterilized via γ-irradiation did increase in EPC0, but this increase was attributed to lysis of the microbial biomass – an overlooked P stock in streams. The study highlights that the sediment P buffer, while largely abiotic in nature, may subsidize microbial P demand in sediment biofilms, thus influencing stream ecological function. The last study examined P uptake at the stream reach scale. Considering two contrasting but predominant controls on stream P uptake – periphyton P demand and sediment P sorption – a natural way to separate the two processes was to measure P uptake under light and dark conditions. Stream gross primary productivity (driven by periphyton) was high as expected for this open-canopy stream. However, this did not translate to an increase in stream P uptake when compared to dark conditions. Sediments were highly sorptive and their relatively low EPC0 suggested a potential for P removal throughout the experiment. Thus the sediment P buffer was likely most responsible for the measured stream P uptake although different stream conditions (e.g., greater nitrogen availability) could increase periphyton’s relevance and should be studied further. In summary, the benthic sediment P buffer can contribute to the regulation of P availability in many streams. Sediments may attenuate P inputs, thus dampening DRP variation at baseflow and prolonging the legacy of past P inputs in the catchment. Stream hydrology (e.g., hyporheic exchange), geochemistry (e.g. pH), and biota (e.g., sediment microbial P demand) are among the chief external factors that may moderate or interact with the sediment P buffer and deserve further study. Predicting P availability in streams remains a major challenge, but understanding the sediment P buffer will greatly improve our ability to prevent stream eutrophication

Trend Analysis of Water Quality in Northwest Arkansas Streams Reflects Changes in the Watershed

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using monitoring data collected from 2009 to 2015. The first case study focused on phosphorus concentrations in the Illinois River watershed and illustrated significant decreases in soluble reactive phosphorus following reductions of effluent phosphorus from upstream wastewater treatment plants. However, no significant trends were found in total phosphorus at the most downstream site on the Illinois River, suggesting that there are legacy sources of phosphorus remaining in the watershed. The second case study focused on nitrogen and phosphorus in the three main inflows to Beaver Lake, where primary productivity will likely cause the lake to violate its water quality standard for chlorophyll-a concentration. Data collected at two sites in Beaver Lake showed elevated chlorophyll-a concentrations and one site near Lowell, Arkansas, the location of a major drinking water supply intake, showed increasing trends from 2001 to 2015 for total nitrogen as well as chlorophyll-a. Monitoring data of the inflows illustrated the variability in hydrological and climatic factors (e.g., drought), which affects nutrient delivery to Beaver Lake. Long-term monitoring of streams in both watersheds will be crucial for understanding the processes that affect water quality and will better inform watershed management

Solving Electrical Engineering Puzzles Using Spatial Reasoning

The precursor of any problem-solving strategy is the visualization of the problem at hand. When dealing with problems pertaining to STEM (science, technology, engineering, and mathematics) areas, visualization plays a very significant role in addressing the same. Several initiatives are being taken to improve the visualization skills of the students and spatial reasoning techniques have proved to be one of the most widely accepted tools for addressing the problems in the STEM field. In this paper, we specifically address the use of spatial reasoning to solve problems in the form of puzzles taken from electrical engineering and analyze the fruitfulness of employing such a strategy. The puzzles are hosted in an online interactive framework called UNTANGLED and classified into different categories on the basis of the nature of the puzzles and their difficulties. The results indicate that spatial reasoning technique indeed helped the players to successfully complete the puzzles. The interpretation of the data led to the conclusion that spatial reasoning techniques are imperative when it comes to discerning and resolving a problem, especially in the STEM domain

Machine learning uncovers the most robust self-report predictors of relationship quality across 43 longitudinal couples studies

Given the powerful implications of relationship quality for health and well-being, a central mission of relationship science is explaining why some romantic relationships thrive more than others. This large-scale project used machine learning (i.e., Random Forests) to 1) quantify the extent to which relationship quality is predictable and 2) identify which constructs reliably predict relationship quality. Across 43 dyadic longitudinal datasets from 29 laboratories, the top relationship-specific predictors of relationship quality were perceived-partner commitment, appreciation, sexual satisfaction, perceived-partner satisfaction, and conflict. The top individual-difference predictors were life satisfaction, negative affect, depression, attachment avoidance, and attachment anxiety. Overall, relationship-specific variables predicted up to 45% of variance at baseline, and up to 18% of variance at the end of each study. Individual differences also performed well (21% and 12%, respectively). Actor-reported variables (i.e., own relationship-specific and individual-difference variables) predicted two to four times more variance than partner-reported variables (i.e., the partner’s ratings on those variables). Importantly, individual differences and partner reports had no predictive effects beyond actor-reported relationship-specific variables alone. These findings imply that the sum of all individual differences and partner experiences exert their influence on relationship quality via a person’s own relationship-specific experiences, and effects due to moderation by individual differences and moderation by partner-reports may be quite small. Finally, relationship-quality change (i.e., increases or decreases in relationship quality over the course of a study) was largely unpredictable from any combination of self-report variables. This collective effort should guide future models of relationships

The ABC130 barrel module prototyping programme for the ATLAS strip tracker

For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.Comment: 82 pages, 66 figure

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P < 0.001) and PARP inhibitor therapy (P < 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P < 0.018) and WEE1 inhibitor (P < 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens