Relationship between water quality, watermilfoil frequency, and weevil distribution in the State of Washington

During the summer of 1997, we surveyed 50 waterbodies in Washington State to determine the distribution of the aquatic weevil Euhrychiopsis lecontei Dietz. We collected data on water quality and the frequency of occurrence of watermilfoil species within selected watermilfoil beds to compare the waterbodies and determine if they were related to the distribution E. lecontei . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature

Studying in vivo dynamics of xylem-transported 11CO2 using positron emission tomography

Respired CO2 in woody tissues can build up in the xylem and dissolve in the sap solution to be transported through the plant. From the sap, a fraction of the CO2 can either be radially diffuse to the atmosphere or be assimilated in chloroplasts present in woody tissues. These processes occur simultaneously in stems and branches, making it difficult to study their specific dynamics. Therefore, an 11C-enriched aqueous solution was administered to young branches of Populus tremula L., which were subsequently imaged by positron emission tomography (PET). This approach allows in vivo visualization of the internal movement of CO2 inside branches at high spatial and temporal resolution, and enables direct measurement of the transport speed of xylem-transported CO2 (vCO2). Through compartmental modeling of the dynamic data obtained from the PET images, we (i) quantified vCO2 and (ii) proposed a new method to assess the fate of xylem-transported 11CO2 within the branches. It was found that a fraction of 0.49 min−1 of CO2 present in the xylem was transported upwards. A fraction of 0.38 min−1 diffused radially from the sap to the surrounding parenchyma and apoplastic spaces (CO2,PA) to be assimilated by woody tissue photosynthesis. Another 0.12 min−1 of the xylem-transported CO2 diffused to the atmosphere via efflux. The remaining CO2 (i.e., 0.01 min−1) was stored as CO2,PA, representing the build-up within parenchyma and apoplastic spaces to be assimilated or directed to the atmosphere. Here, we demonstrate the outstanding potential of 11CO2-based plant-PET in combination with compartmental modeling to advance our understanding of internal CO2 movement and the respiratory physiology within woody tissues

SPRAY FOAM IN ACCESSIBLE SPACES:BEST PRACTICES AND CASE STUDIES FOR RETROFIT IN MIXED-HUMID CLIMATE

Heating and cooling the house is one of the homeowners major expenses. Reducing these costs, saving energy, and creating a healthier, more comfortable indoor environment are good reasons to consider improving the building thermal envelope. Improvements usually consider increasing the amount of insulation, reducing the infiltration of outside air, and controlling moisture in existing buildings. This report describes the use of spray foam materials to insulate, seal, and control moisture. This discussion is limited to treating areas that are accessible. What is accessible, however, can vary depending on the type of renovation. If the building has been gutted or exterior surfaces removed, there are more options. This report will look at areas to consider for spray foam application and discuss the types of spray foams available and their uses. A number of case studies are presented to show the effectiveness of this retrofit in existing houses based on performance data

The spread of COVID-19 in London: network effects and optimal lockdowns

We generalise a stochastic version of the workhorse SIR (Susceptible-Infectious- Removed) epidemiological model to account for spatial dynamics generated by network interactions. Using the London metropolitan area as a salient case study, we show that commuter network externalities account for about 42% of the propagation of COVID-19. We find that the UK lockdown measure reduced total propagation by 57%, with more than one third of the effect coming from the reduction in network externalities. Counterfactual analyses suggest that: i) the lockdown was somehow late, but further delay would have had more extreme consequences; ii) a targeted lockdown of a small number of highly connected geographic regions would have been equally effective, arguably with significantly lower economic costs; iii) targeted lockdowns based on threshold number of cases are not effective, since they fail to account for network externalities

The CRAFTS learning framework: equipping learners to create relevant, accessible, fun, tailored and scholarly activities in higher education

Tertiary institutions are migrating away from didactic and teacher-centred approaches, and instead, pivoting to lesson designs that encourage hands-on learning and student engagement. However, this practice is often “try and see”, with few frameworks providing evidence-based approaches for practical application that demonstrates how learning can be successfully achieved. The literature supports foundational concepts that can be applied to develop effective learning environments, where students become producers, rather than consumers of course content. The CRAFTS framework outlines the benefits of focussing on: Create, Relevant, Accessible, Fun, Tailored and Scholarly activities and interventions to guide and facilitate student learning. This article presents the framework, an example application of its employment within a tertiary health science and medicine subject, and an evaluation of its effectiveness. For educators wishing to engage students in learning methods that extend beyond traditional didactic teaching delivery modes, and instead, focus on learner-centred approaches, this framework embeds the concepts of creativity, relevance, accessibility, and fun into sessions that can be tailored to the individual learner and are scholarly in nature. In these ways, the CRAFTS framework presents a robust and evidence-based approach to encouraging hands-on learner-generated content that can be used for knowledge consolidation in a tertiary course

Network risk and key players: a structural analysis of interbank liquidity

We model banks' liquidity holding decision as a simultaneous game on an interbank borrowing network. We show that at the Nash equilibrium, the contributions of each bank to the network liquidity level and liquidity risk are distinct functions of its indegree and outdegree Katz-Bonacich centrality measures. A wedge between the planner and the market equilibria arises because individual banks do not internalize the effect of their liquidity choice on other banks' liquidity benefit and risk exposure. The network can act as an absorbent or a multiplier of individual banks' shocks. Using a sterling interbank network database from January 2006 to September 2010, we estimate the model in a spatial error framework, and find evidence for a substantial, and time varying, network risk: in the period before the Lehman crisis, the network is cohesive and liquidity holding decisions are complementary and there is a large network liquidity multiplier; during the 2007-08 crisis, the network becomes less clustered and liquidity holding less dependent on the network; after the crisis, during Quantitative Easing, the network liquidity multiplier becomes negative, implying a lower network potential for generating liquidity. The network impulse-response functions indicate that the risk key players during these periods vary, and are not necessarily the largest borrowers

The Triple-S framework: ensuring scalable, sustainable, and serviceable practices in educational technology

Educational institutions are increasingly investing into digital delivery, acquiring new devices, and employing novel software and services. The rising costs associated with maintenance, in combination with increasing redundancy of older technologies, presents multiple challenges. While lesson content itself may not have changed, the educational landscape constantly evolves, where tertiary institutions are incorporating new modes of content delivery, hybrid-style learning, and interactive technologies. Investments into digital expansions must be taken with caution, particularly prior to the procurement of technology, with a need for the proposed interventions’ scalability, sustainability, and serviceability to be considered. This article presents the Triple-S framework for educators, administrators, and educational institutions, and outlines examples of its application within curricula. The paper synthesises research evidence to provide the foundation underlying the key principles of the Triple-S framework, presenting a useful model to use when evaluating digital interventions. Utilising the framework for decisions regarding the acquisition of educational technology, devices, software, applications, and online resources can assist in the assurance of viable and appropriate investments

Guide to plant-PET imaging using 11CO2

Due to its high sensitivity and specificity for tumor detection, positron emission tomography (PET) has become a standard and widely used molecular imaging technique. Given the popularity of PET, both clinically and preclinically, its use has been extended to study plants. However, only a limited number of research groups worldwide report PET-based studies, while we believe that this technique has much more potential and could contribute extensively to plant science. The limited application of PET may be related to the complexity of putting together methodological developments from multiple disciplines, such as radio-pharmacology, physics, mathematics and engineering, which may form an obstacle for some research groups. By means of this manuscript, we want to encourage researchers to study plants using PET. The main goal is to provide a clear description on how to design and execute PET scans, process the resulting data and fully explore its potential by quantification via compartmental modeling. The different steps that need to be taken will be discussed as well as the related challenges. Hereby, the main focus will be on, although not limited to, tracing 11CO2 to study plant carbon dynamics