Collapse and recovery of forage fish populations prior to commercial exploitation

We use a new, well‐calibrated 500 year paleorecord off southern California to determine collapse frequency, cross correlation, persistence, and return times of exploited forage fish populations. The paleorecord shows that “collapse” (defined as <10% of the mean peak biomass) is a normal state repeatedly experienced by northern anchovy, Pacific hake, and Pacific sardine which were collapsed 29–40% of the time, prior to commercial fishing exploitation. Mean (± SD) persistence of “fishable biomass” (defined as one third mean peak biomass from the paleorecord) was 19 ± 18, 15 ± 17, and 12 ± 7 years for anchovy, hake, and sardine. Mean return times to the same biomass was 8 years for anchovy but 22 years for sardine and hake. Further, we find that sardine and anchovy are positively correlated over 400 years, consistent with coherent declines of both species off California. Persistence and return times combined with positive sardine‐anchovy correlation indicate that on average 1–2 decades of fishable biomass will be followed by 1–2 decades of low forage. Forage populations are resilient on the 500 year time scale, but their collapse and recovery cycle (based on the paleorecord) are suited to alternating periods of high fishing mortality and periods of little or no fishing.Key PointsThe paleorecord shows that “collapse” is a normal state repeatedly experienced by northern anchovy, Pacific hake, and Pacific sardineMean return times to “fishable” biomass was 8 years for anchovy, but 22 years for sardine and hake, and persistence was of the same orderSardine and anchovy are positively correlated over 400 years, consistent with coherent declines of both species off CaliforniaPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136405/1/grl55551.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136405/2/grl55551_am.pd

Geochronological studies in Santa Barbara Basin: <SUP>55</SUP>Fe as a unique tracer for particulate settling

Sediments accumulate in the Santa Barbara Basin relatively rapidly: about 3-4 mm yr-1 based on the analysis of varves. These deposits are ideal for studying the applicability of nuclear geochronological techniques in a natural situation. Studies of the depth distribution of several radionuclides, manmade 55Fe and naturally occurring 210Pb and Th isotopes, in recent Santa Barbara sediment layers permit an evaluation of the geochemical behavior of Fe, Pb, and Th in coastal waters and have established the usefulness of 55Fe and 210Pb for dating coastial or near coastal sediments deposited during the last decade and half-century respectively

Engaging stakeholders in research to address water-energy-food (WEF) nexus challenges

The water–energy–food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs—in this case orientated around a number of cases studies—are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making

Identifying influencers on social media

© 2020 Elsevier Ltd The increased availability of social media big data has created a unique challenge for marketing decision-makers; turning this data into useful information. One of the significant areas of opportunity in digital marketing is influencer marketing, but identifying these influencers from big data sets is a continual challenge. This research illustrates how one type of influencer, the market maven, can be identified using big data. Using a mixed-method combination of both self-report survey data and publicly accessible big data, we gathered 556,150 tweets from 370 active Twitter users. We then proposed and tested a range of social-media-based metrics to identify market mavens. Findings show that market mavens (when compared to non-mavens) have more followers, post more often, have less readable posts, use more uppercase letters, use less distinct words, and use hashtags more often. These metrics are openly available from public Twitter accounts and could integrate into a broad-scale decision support system for marketing and information systems managers. These findings have the potential to improve influencer identification effectiveness and efficiency, and thus improve influencer marketing

The psychological impact of COVID19 on a shielding high-risk cohort

No abstract available

Unintended consequences: Unknowable and unavoidable, or knowable and unforgivable?

This is the final version. Available on open access from Frontiers Media via the DOI in this recordRecognizing that there are multiple environmental limits within which humanity can safely operate, it is essential that potential negative outcomes of seemingly positive actions are accounted for. This alertness to unintended consequences underscores the importance of so called ‘nexus’ research, which recognizes the integrated and interactive nature of water, energy and food systems, and aims to understand the broader implications of developments in any one of these systems. This article presents a novel framework for categorizing such detrimental unintended consequences, based upon how much is known about the system in question and the scope for avoiding any such unintended consequences. The framework comprises four categories (Knowable and Avoidable; Knowable and Unavoidable; Unknowable and Avoidable, and Unknowable and Unavoidable). The categories are explored with reference to examples in both the water-energy-food nexus and planetary boundary frameworks. The examples highlight the potential for the unexpected to happen and explore dynamic nature of the situations that give rise to the unexpected. The article concludes with guidance on how the framework can be used to increase confidence that best efforts have been made to navigate our way towards secure and sustainable water, energy and food systems, avoiding and/or managing unintended consequences along the way.Engineering and Physical Sciences Research Council (EPSRC

Inhibition of LRRK2 kinase activity stimulates macroautophagy

Leucine Rich Repeat Kinase 2 (LRRK2) is one of the most important genetic contributors to Parkinson's disease. LRRK2 has been implicated in a number of cellular processes, including macroautophagy. To test whether LRRK2 has a role in regulating autophagy, a specific inhibitor of the kinase activity of LRRK2 was applied to human neuroglioma cells and downstream readouts of autophagy examined. The resulting data demonstrate that inhibition of LRRK2 kinase activity stimulates macroautophagy in the absence of any alteration in the translational targets of mTORC1, suggesting that LRRK2 regulates autophagic vesicle formation independent of canonical mTORC1 signaling. This study represents the first pharmacological dissection of the role LRRK2 plays in the autophagy/lysosomal pathway, emphasizing the importance of this pathway as a marker for LRRK2 physiological function. Moreover it highlights the need to dissect autophagy and lysosomal activities in the context of LRRK2 related pathologies with the final aim of understanding their aetiology and identifying specific target for disease modifying therapies in patients

Anaerobic digestion: A prime solution for water, energy and food nexus challenges

This is the final version. Available on open access from Elsevier via the DOI in this record1st International Conference on Sustainable Energy and Resource Use in Food Chains, ICSEF 2017, 19-20 April 2017, Berkshire, UKWe solve the problem of identifying one or more optimal patterns of anaerobic digestion (AD) installation across the UK, by considering existing installations, the current feedstock potential and the project growth of the potential via population, demography and urbanization. We test several scenarios for the level of adoption of the AD operations in the community under varying amounts of feedstock supply, which may arise from change in food waste or energy crops generation via other policies and incentives. For the most resilient scales of solutions, we demonstrate for the UK the net energy production (bio-gas and electricity) from AD (and so the avoided emissions from grid energy), the mass of bio-waste processed (and avoided land-fill), and the quantum of digestate produced (as a proxy for avoided irrigation and fertilizer production). In order to simulate the AD innovation within WEF nexus we use agent based modelling (ABM) owing to its bottom-up approach and capability of modelling complex systems with relatively low level data and information