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Abstract Labor abuse on fishing vessels and illegal, unreported and unregulated (IUU) fishing violate human rights, jeopardize food security, and deprive governments of revenues. We applied a multi-method approach, combining new empirical data with satellite information on fishing activities and vessel characteristics to map risks of labor abuse and IUU fishing, understand their relationships, and identify major drivers. Port risks were globally pervasive and often coupled, with 57% of assessed ports associated with labor abuse or IUU fishing. For trips ending in assessed ports, 82% were linked to labor abuse or IUU fishing risks. At-sea risk areas were primarily driven by fishing vessel flags linked to poor control of corruption by the flag state, high ownership by countries other than the flag state, and Chinese-flagged vessels. Transshipment risk areas were related to the gear type of fishing vessels engaged in potential transshipment and carrier vessel flags. Measures at port offer promise for mitigating risks, through the Port State Measures Agreement for IUU fishing, and ensuring sufficient vessel time at port to detect and respond to labor abuse. Our results highlight the need for coordinated action across actors to avoid risk displacement and make progress towards eliminating these socially, environmentally and economically unsustainable practices. 

Polymer networks crosslinked with spring-like ortho -phenylene ( o P) foldamers were developed. NMR analysis indicated the o P crosslinkers were well-folded. Polymer networks with o P-based crosslinkers showed enhanced energy dissipation and elasticity compared to divinylbenzene crosslinked networks. The energy dissipation was attributed to the strain-induced reversible unfolding of the o P units. Energy dissipation increased with the number of helical turns in the foldamer. 

Interpenetrating networks (IPN) comprise two or more networks which are woven but not covalently bonded to each other. This is in contrast to simple, or single Networks (SN), which contain only one network that is covalently crosslinked. This study develops SNs and IPNs using 2-hydroxyethyl acrylate as the monomer and (2-((1-(2-(acryloyloxy)ethyl)-2,5-dioxopyrrolidin-3-yl) thio)ethyl acrylate) (TMMDA) as a thermoresponsive dynamic thiol-Michael crosslinker. In the case of the IPN and SN materials the TMMDA is used as a thermoresponsive linker in each network, since TMMDA undergoes dynamic covalent exchange above 90 °C. In this way the SN and IPNs are kinetically trapped in their as synthesized structures until exposed to thermal stimulus. The focus of this study is to investigate how dynamic bond exchange can modulate material properties, after the material has been synthesized using the SN and IPN materials as model systems. The dynamic nature of the thiol-Michael crosslinker allows the transition of IPNs into SN like structures above 90 °C resulting in similar polymer architecture in both SN and IPN. Surprisingly, upon heating the SN materials also changed their mechanical properties, upon activation of the dynamic thiol-Michael bonds. This enhancement is proposed to occur by thermally activating the thiol-Michael bonds and reducing the number of floppy loops at higher temperature. 

A one pot synthesis is applied to control the chain structure and architecture of multiply dynamic polymers, enabling fine tuning of materials properties by choice of polymer chain length or crosslink density. Macromolecules containing both non-covalent linkers based on quadruple hydrogen-bonded 2-(((6-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)hexyl)carbamoyl)oxy)ethyl methacrylate (UPyMA), and thermoresponsive dynamic covalent furan–maleimide based Diels–Alder linkers are explored. The primary polymer's architecture was controlled by reversible addition-fragmentation chain transfer (RAFT) polymerization, with the dynamic non-covalent (UPyMA) and dynamic covalent furfuryl methacrylate (FMA) units incorporated into the same backbone. The materials are crosslinked, taking advantage of the “click” chemistry properties of the furan–maleimide reaction. The polymer materials showed stimulus-responsive thermomechanical properties with a decrosslinking temperature increasing with the polymer's primary chain length and crosslink density. The polymers had good thermally promoted self-healing properties due to the dynamic covalent Diels–Alder bonds. Besides, the materials had excellent stress relaxation characteristics induced by the exchange of the hydrogen bonds in UPyMA units. 

Abstract Colorectal cancer and other cancers often metastasize to the liver in later stages of the disease, contributing significantly to patient death. While the biomechanical properties of the liver parenchyma (normal liver tissue) are known to affect tumor cell behavior in primary and metastatic tumors, the role of these properties in driving or inhibiting metastatic inception remains poorly understood, as are the longer-term multicellular dynamics. This study adopts a multi-model approach to study the dynamics of tumor-parenchyma biomechanical interactions during metastatic seeding and growth. We employ a detailed poroviscoelastic model of a liver lobule to study how micrometastases disrupt flow and pressure on short time scales. Results from short-time simulations in detailed single hepatic lobules motivate constitutive relations and biological hypotheses for a minimal agent-based model of metastatic growth in centimeter-scale tissue over months-long time scales. After a parameter space investigation, we find that the balance of basic tumor-parenchyma biomechanical interactions on shorter time scales (adhesion, repulsion, and elastic tissue deformation over minutes) and longer time scales (plastic tissue relaxation over hours) can explain a broad range of behaviors of micrometastases, without the need for complex molecular-scale signaling. These interactions may arrest the growth of micrometastases in a dormant state and prevent newly arriving cancer cells from establishing successful metastatic foci. Moreover, the simulations indicate ways in which dormant tumors could “reawaken” after changes in parenchymal tissue mechanical properties, as may arise during aging or following acute liver illness or injury. We conclude that the proposed modeling approach yields insight into the role of tumor-parenchyma biomechanics in promoting liver metastatic growth, and advances the longer term goal of identifying conditions to clinically arrest and reverse the course of late-stage cancer.