Actin Dynamics Regulate Myosin Assembly in Muscle Cells

During muscle cell (i.e. myocyte )development, organization of actin and myosin into the contractile unit (i.e. sarcomere) is required for proper muscle contraction. By disrupting the processes of muscle cell development, I am able to see which steps play important roles in proper maturation of myocytes. Elucidation of the key pathways in muscle development could lead to a better understanding of human cardiac hypertrophies and muscle myopathies. Since actin filament formation precedes myosin organization, I am using actin assembly inhibitors to determine if actin filaments are a necessary prerequisite for myosin organization. It is hypothesized that disruption of actin will disrupt myosin organization. In these experiments Jasplakinolide (Jasp) is applied to cultured embryonic myocytes during sarcomere assembly. Jasp binds, stabilizes, and induces polymerization of actin filaments (i.e. F-actin) making it a useful compound for determining if actin dynamics or precise thin filament length are necessary for myosin incorporation into the sarcomere. My results indicate that normal actin organization is required for correct sarcomere development. Myosin organization was reduced by more than 90% in all treatment regimes (50, 100, and 500 nanomolar Jasp). Sarcomeres failed to form and myosin appeared diffuse throughout the myocytes. Mv results indicate that intact, precisely regulated thin filaments are a prerequisite for normal myosin assembly. It remains to be determined if this requirement stems from actin-titin interactions, actin-myosin cross-bridge formation, or some other intermolecular interactions. Hopefully a better understanding of how sarcomeres form will provide insight into diseases involving the improper assembly of muscle such as myopathies or hypertrophies

Actin Dynamics Regulate Myosin Assembly in Muscle Cells

During muscle cell (i.e. myocyte )development, organization of actin and myosin into the contractile unit (i.e. sarcomere) is required for proper muscle contraction. By disrupting the processes of muscle cell development, I am able to see which steps play important roles in proper maturation of myocytes. Elucidation of the key pathways in muscle development could lead to a better understanding of human cardiac hypertrophies and muscle myopathies. Since actin filament formation precedes myosin organization, I am using actin assembly inhibitors to determine if actin filaments are a necessary prerequisite for myosin organization. It is hypothesized that disruption of actin will disrupt myosin organization. In these experiments Jasplakinolide (Jasp) is applied to cultured embryonic myocytes during sarcomere assembly. Jasp binds, stabilizes, and induces polymerization of actin filaments (i.e. F-actin) making it a useful compound for determining if actin dynamics or precise thin filament length are necessary for myosin incorporation into the sarcomere. My results indicate that normal actin organization is required for correct sarcomere development. Myosin organization was reduced by more than 90% in all treatment regimes (50, 100, and 500 nanomolar Jasp). Sarcomeres failed to form and myosin appeared diffuse throughout the myocytes. Mv results indicate that intact, precisely regulated thin filaments are a prerequisite for normal myosin assembly. It remains to be determined if this requirement stems from actin-titin interactions, actin-myosin cross-bridge formation, or some other intermolecular interactions. Hopefully a better understanding of how sarcomeres form will provide insight into diseases involving the improper assembly of muscle such as myopathies or hypertrophies

Wafers in Saddle Bags: A Novel Dispensing System for Male Lures Used to Detect Invasive Fruit Flies (Diptera: Tephritidae)

Detection of the agricultural pests Bactrocera dorsalis (Hendel) and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) relies heavily on traps baited with male-specific attractants. For B. dorsalis, traps are baited with liquid (6 ml) methyl eugenol (ME), while polymeric plugs containing trimedlure (TML; 2 g) are used in traps targeting C. capitata. In both cases, the attractant volatilizes rapidly, and lures are changed out every 6 weeks to insure high trap attractancy. Lures having greater longevity would be beneficial, because they would lengthen the trap servicing interval and thus reduce both supply and labor costs. Here, we tested the effectiveness of a saddle bag dispenser that (i) held two solid wafers impregnated with male lure, thus eliminating handling of liquid methyl eugenol (a potential carcinogen), (ii) was easy to place in traps, and (iii) allowed a high loading of male lure in trap (total loading of 6 g per trap for each lure). Field experiments, each lasting 12–14 weeks, were conducted on Hawaii island and Oahu, Hawaii, that compared captures of B. dorsalis and C. capitata males in traps baited in the standard manner versus traps baited with saddle bag dispensers. Traps baited with ME saddle bags weathered up to 12 or 14 weeks generally captured similar numbers of B. dorsalis males as traps baited with fresh ME liquid and significantly more males than traps baited with weathered ME liquid. Similar results were obtained for C. capitata: traps baited with TML saddle bags weathered up to 12 or 14 weeks captured similar numbers of C. capitata males as traps baited with fresh TML plugs and significantly more males than traps baited with weathered TML plugs

Sipping Tea and Sharing Kōrero: Reflections on ‘Activating Collectivity: Aroha and Power’

Over literal and metaphorical cups of tea, the organising crew of ‘Activating Collectivity: Aroha and Power’ reflect on what went into planning and shaping the conference and what was gained from it. In doing so, they invite readers to grab a cup and join in the reflective process

Racial/ethnic differences in Child Protective Services reporting, substantiation, and placement, with comparison to non-CPS risks and outcomes: 2005—2019

We used National Child Abuse and Neglect Data System and Census data to examine Black–White and Hispanic–White disparities in reporting, substantiation, and out-of-home placement both descriptively from 2005–2019 and in multivariate models from 2007–2017. We also tracked contemporaneous social risk (e.g., child poverty) and child harm (e.g., infant mortality) disparities using non-child protective services (CPS) sources and compared them to CPS reporting rate disparities. Black–White CPS reporting disparities were lower than found in non-CPS risk and harm benchmarks. Consistent with the Hispanic paradox, Hispanic–White CPS reporting disparities were lower than risk disparities but similar to harm disparities. Descriptive and multivariate analyses of data from the past several years indicated that Black children were less likely to be substantiated or placed into out-of-home care following a report than White children. Hispanic children were slightly more likely to be substantiated or placed in out-of-home care than White children overall, but this difference disappeared in multivariate models. Available data provide no evidence that Black children were overreported relative to observed risks and harms reflected in non-CPS data. Reducing reporting rates among Black children will require addressing broader conditions associated with maltreatment

Sustainable management of groundwater extraction: An Australian perspective on current challenges

Study focus: Our incomplete knowledge of groundwater systems and processes imposes barriers in attempting to manage groundwater sustainably. Challenges also arise through complex institutional arrangements and decision-making processes, and the difficulty in involving stakeholders. In some areas, these difficulties have led to water table decline and impacts on groundwater users and groundwater-dependent ecosystems. However, there is potential to improve the sustainable use of groundwater resources through improvements in management practices. We discuss some of the challenges, and present survey results of research, government, and industry professionals across the groundwater sector in Australia. New hydrological insights for the region: The highest-ranked challenge identified in the survey was the difficulty in determining regional-scale volumetric water extraction limits. This is surprising given the criticism in the international literature of volumetric based approaches for groundwater management, and the decreased reliance on this approach in Australia and elsewhere in recent years. Other major challenges are the difficulty in determining and implementing maximum drawdown criteria for groundwater levels, determining water needs of ecosystems, and managing groundwater impacts on surface water. Notwithstanding these gaps in technical understanding and tools and a lack of resources for groundwater studies, improvements in stakeholder communication should enable more effective decision-making and improve compliance with regulations designed to protect groundwater and dependent ecosystems

Training future generations to deliver evidence-based conservation and ecosystem management

1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice. 3. To help overcome this problem we have created open access online teaching materials in multiple languages that are stored in Applied Ecology Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision-making. This includes 145 undergraduate, postgraduate or professional development courses. 4. We call for wider teaching of the tools and skills that facilitate evidence-based conservation and also suggest that providing online teaching materials in multiple languages could be beneficial for improving global understanding of other subject areas.Peer reviewe

Simulating carbon accumulation and loss in the central Congo peatlands

Peatlands of the central Congo Basin have accumulated carbon over millennia. They currently store some 29 billion tonnes of carbon in peat. However, our understanding of the controls on peat carbon accumulation and loss and the vulnerability of this stored carbon to climate change is in its infancy. Here we present a new model of tropical peatland development, DigiBog_Congo, that we use to simulate peat carbon accumulation and loss in a rain-fed interfluvial peatland that began forming ~20,000 calendar years Before Present (cal. yr BP, where ‘present’ is 1950 CE). Overall, the simulated age-depth curve is in good agreement with palaeoenvironmental reconstructions derived from a peat core at the same location as our model simulation. We find two key controls on long-term peat accumulation: water at the peat surface (surface wetness) and the very slow anoxic decay of recalcitrant material. Our main simulation shows that between the Late Glacial and early Holocene there were several multidecadal periods where net peat and carbon gain alternated with net loss. Later, a climatic dry phase beginning ~5200 cal. yr BP caused the peatland to become a long-term carbon source from ~3975 to 900 cal. yr BP. Peat as old as ~7000 cal. yr BP was decomposed before the peatland's surface became wetter again, suggesting that changes in rainfall alone were sufficient to cause a catastrophic loss of peat carbon lasting thousands of years. During this time, 6.4 m of the column of peat was lost, resulting in 57% of the simulated carbon stock being released. Our study provides an approach to understanding the future impact of climate change and potential land-use change on this vulnerable store of carbon

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits