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

Evaluation of a system for segmental speech quality assessment: Voiceless fricavties.

In this paper, an automatic assessment procedure for monitoring the speech progress of patients who have undergone intra-oral surgery is evaluated. The metric is currently limited to fricative segments and is based on centroid analysis of the speech spectra. The scores provided by this means are correlated with an articulatory assessment provided by a panel of 3 phoneticians. Preliminary results show a degree of correlation between mean panel scores for perceived quality and scores relating to this measure obtained by computer analysis but lateral and nasal co-articulation are not well represented by the metric

Two novel missense mutations in ABCA1 result in altered trafficking and cause severe autosomal recessive HDL deficiency

AbstractExtremely low concentrations of high density lipoprotein (HDL)-cholesterol and apolipoprotein (apo) AI are features of Tangier disease caused by autosomal recessive mutations in ATP-binding cassette transporter A1 (ABCA1). Less deleterious, but dominantly inherited mutations cause HDL deficiency. We investigated causes of severe HDL deficiency in a 42-year-old female with progressive coronary disease.ApoAI-mediated efflux of cholesterol from the proband's fibroblasts was less than 10% of normal and nucleotide sequencing revealed inheritance of two novel mutations in ABCAI, V1704D and L1379F. ABCA1 mRNA was approximately 3-fold higher in the proband's cells than in control cells; preincubation with cholesterol increased it 5-fold in control and 8-fold in the proband's cells, but similar amounts of ABCA1 protein were present in control and mutant cells. When transiently transfected into HEK293 cells, confocal microscopy revealed that both mutant proteins were retained in the endoplasmic reticulum, while wild-type ABCA1 was located at the plasma membrane.Severe HDL deficiency in the proband was caused by two novel autosomal recessive mutations in ABCA1, one (V1704D) predicted to lie in a transmembrane segment and the other (L1379F) in a large extracellular loop. Both mutations prevent normal trafficking of ABCA1, thereby explaining their inability to mediate apoA1-dependent lipid efflux

Adaptively monitoring streamflow using a stereo computer vision system

The gauging of free surface flows in waterways provides the foundation for monitoring and managing the water resources of built and natural environments. A significant body of literature exists around the techniques and benefits of optical surface velocimetry methods to estimate flows in waterways without intrusive instruments or structures. However, to date, the operational application of these surface velocimetry methods has been limited by site configuration and inherent challenging optical variability across different natural and constructed waterway environments. This work demonstrates a significant advancement in the operationalisation of non-contact stream discharge gauging applied in the computer vision stream gauging (CVSG) system through the use of methods for remotely estimating water levels and adaptively learning discharge ratings over time. A cost-effective stereo camera-based stream gauging device (CVSG device) has been developed for streamlined site deployments and automated data collection. Evaluations between reference state-of-the-art discharge measurement technologies using DischargeLab (using surface structure image velocimetry), Hydro-STIV (using space–time image velocimetry), acoustic Doppler current profilers (ADCPs), and gauging station discharge ratings demonstrated that the optical surface velocimetry methods were capable of estimating discharge within a 5 %–15 % range between these best available measurement approaches. Furthermore, results indicated model machine learning approaches leveraging data to improve performance over a period of months at the study sites produced a marked 5 %–10 % improvement in discharge estimates, despite underlying noise in stereophotogrammetry water level or optical flow measurements. The operationalisation of optical surface velocimetry technology, such as CVSG, offers substantial advantages towards not only improving the overall density and availability of data used in stream gauging, but also providing a safe and non-contact approach for effectively measuring high-flow rates while providing an adaptive solution for gauging streams with non-stationary characteristics.</p

Bi-allelic JAM2 Variants Lead to Early-Onset Recessive Primary Familial Brain Calcification.

Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis. We report four unrelated families presenting with initial learning difficulties and seizures and later psychiatric symptoms, cerebellar ataxia, extrapyramidal signs, and extensive calcifications on brain imaging. Through a combination of homozygosity mapping and exome sequencing, we mapped this phenotype to chromosome 21q21.3 and identified bi-allelic variants in JAM2. JAM2 encodes for the junctional-adhesion-molecule-2, a key tight-junction protein in blood-brain-barrier permeability. We show that JAM2 variants lead to reduction of JAM2 mRNA expression and absence of JAM2 protein in patient's fibroblasts, consistent with a loss-of-function mechanism. We show that the human phenotype is replicated in the jam2 complete knockout mouse (jam2 KO). Furthermore, neuropathology of jam2 KO mouse showed prominent vacuolation in the cerebral cortex, thalamus, and cerebellum and particularly widespread vacuolation in the midbrain with reactive astrogliosis and neuronal density reduction. The regions of the human brain affected on neuroimaging are similar to the affected brain areas in the myorg PFBC null mouse. Along with JAM3 and OCLN, JAM2 is the third tight-junction gene in which bi-allelic variants are associated with brain calcification, suggesting that defective cell-to-cell adhesion and dysfunction of the movement of solutes through the paracellular spaces in the neurovascular unit is a key mechanism in CNS calcification

AKT signalling selectively regulates PINK1 mitophagy in SHSY5Y cells and human iPSC-derived neurons

The discovery of mutations within genes associated with autosomal recessive Parkinson's disease allowed for the identification of PINK1/Parkin regulated mitophagy as an important pathway for the removal of damaged mitochondria. While recent studies suggest that AKT-dependent signalling regulates Parkin recruitment to depolarised mitochondria, little is known as to whether this can also regulate PINK1 mitochondrial accumulation and downstream mitophagy. Here, we demonstrate that inhibition of AKT signalling decreases endogenous PINK1 accumulation in response to mitochondria depolarisation, subsequent Parkin recruitment, phosphorylation of ubiquitin, and ultimately mitophagy. Conversely, we show that upon stimulation of AKT signalling via insulin, the mitophagy pathway is increased in SHSY5Y cells. These data suggest that AKT signalling is an upstream regulator of PINK1 accumulation on damaged mitochondria. Importantly, we show that the AKT pathway also regulates endogenous PINK1-dependent mitophagy in human iPSC-derived neurons