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Abstract The ring-shaped cohesin complex is a key player in sister chromatid cohesion, DNA repair, and gene transcription. The loading of cohesin to chromosomes requires the loader Scc2 and is regulated by ATP. This process is hindered by Smc3 acetylation. However, the molecular mechanism underlying this inhibition remains mysterious. Here, using Saccharomyces cerevisiae as a model system, we identify a novel configuration of Scc2 with pre-engaged cohesin and reveal dynamic conformations of the cohesin/Scc2 complex in the loading reaction. We demonstrate that Smc3 acetylation blocks the association of Scc2 with pre-engaged cohesin by impairing the interaction of Scc2 with Smc3’s head. Lastly, we show that ATP binding induces the cohesin/Scc2 complex to clamp DNA by promoting the interaction between Scc2 and Smc3 coiled coil. Our results illuminate a dynamic reconfiguration of the cohesin/Scc2 complex during loading and indicate how Smc3 acetylation and ATP regulate this process.

Using single-molecule visualization and manipulation, Chang et al. show that the eukaryotic Smc5/6 complex preferentially binds to and stabilizes ssDNA-dsDNA junctions, which could serve as the molecular basis for its diverse roles in genome maintenance.

Pearl culture in Fiji relies on a supply of pearl oysters obtained through the strategic deployment of spat collectors. Although the design and deployment of spat collectors aim to maximize the recruitment of pearl oysters (Pinctada and Pterin spp.), this activity incidentally captures many other bivalves as bycatch. This study explored whether tropical rock oysters (specifically Magallana bilineata and Saecostrea spp.) were present and sufficiently abundant as bycatch from pearl oyster spat collectors, to support additional commercial opportunities. The results showed that the absolute (0.7 [+ or -] 2.1 spat collector-1) and proportional (2.9% of all bivalves) abundance of these taxa was very low, which would limit oyster harvest in meaningful quantities. Although the prospect of creating additional revenue streams from bycatch could be seen as an incentive to on-grow and sell tropical rock oysters despite their low abundance, it is argued that greater benefit would come from prioritizing activities related to pearl oysters and associated downstream products such as mabe pearl, shellcraft, and pearl-meat production. Ultimately, existing spat collection activities within the cultured pearl sector did not have the anticipated potential to support supplemental aquaculture of tropical rock oysters. KEY WORDS: Fiji, spat collection, fouling, bycatch, tropical rock oyster, Saecostrea, Magallana bilineata, INTRODUCTION Tropical rock oysters are excellent candidates for aquaculture (Angell 1986, Nowland et al. 2020). They are consumed almost everywhere they occur (M unro 1994, Kinch et al. 2019a, Simard [...]

Abstract Background Testing for insulin dysregulation (ID) in horses is commonly performed to guide management and therapeutic strategies. Objectives To evaluate a newly developed glycemic pellets challenge (GPC) and compare results to those obtained using the low‐dose oral sugar test (OST). Animals Twenty‐four adult horses with unknown insulin status. Methods A randomized crossover trial was performed. Horses underwent GPC (0.5 g glycemic carbohydrates/kg body weight) and OST (0.15 mL corn syrup/kg body weight) 7 days apart. Feed was withheld before testing and blood samples were collected at T0, T60, T120, and T180 minutes for GPC and at T0, T60, and T90 minutes for OST. Blood glucose concentration was measured using a point‐of‐care glucometer and insulin by radioimmunoassay. Comparisons were made using nonparametric tests, linear regression, and Bland‐Altman agreement analysis. Results Eighteen horses consumed >85% of the GPC pellets within 10 minutes and had acceptable OST results. Maximum glucose (P = .02) and insulin (P = .007) concentrations were significantly higher for GPC compared with OST. Time to maximum insulin concentration (Tmax[ins]) varied within and between tests and neither Tmax[ins] (P = .28) nor maximum insulin concentration (P = .46) was correlated with the time horses took to consume pellets. Conclusions The GPC is well tolerated and may offer another diagnostic testing modality for ID. Blood glucose and insulin concentrations increase during GPC and reach higher concentrations than observed with low‐dose OST. The Tmax[ins] varied for GPC and OST, emphasizing the importance of identifying the optimal time range for the collection of samples to capture diagnostically relevant changes in insulin concentration.

There is considerable interest in improving hatchery production of the mud crab, Scylla serrata. Although some progress has been made toward identifying appropriate feeding protocols for live-foods, the density at which food is first provided to larvae varies greatly in practice. This study examined relationships between rotifer density and activity patterns of enzymes critical to digestion in S. serrata to evaluate feeding protocols from a nutrient utilization perspective. Activities of trypsin-like proteases, nonspecific esterases, and [alpha]-amylase were quantified to determine the response of newly hatched (Zoea I) larvae of S. serrata to rotifers provided at four different densities (i.e., 10, 20,40, and [80mL.sup.-1]) from first-feeding. Results showed that rotifer density significantly (P < 0.01) influenced total activity (mU [larva.sup.-1]) patterns within 24h of first-feeding for all the enzymes assayed. Based on these patterns, utilization of the associated macronutrients (i.e., protein, lipid, and carbohydrate) was presumably similar when larvae were provided with rotifers at densities of 10, 20, or 40 [mL.sup.-1] and increased when larvae were provided with rotifers at a density of 80 [mL.sup.-1]. An optimal density at which to provide rotifers to S. serrata for first-feeding is likely to be >[40mL.sup.-1]. The comparative analyses of enzyme activities presented in this study represent an innovative approach to quickly (within 24 h) identify optimal food densities for larval crustaceans at first-feeding. KEY WORDS: Portunidae, Scylla serrata, mud crab, hatchery production, first-feeding, rotifers, enzyme activity patterns, INTRODUCTION Crabs of the genus Scylla, commonly referred to as mud crabs, have a complex life cycle, where larvae progress through five to six zoeal stages (3-5 days each) and [...]

Adductor muscle from Pinctada maxima and Pinctada margaritifera were analyzed for nutrient compositions. Both were characterized by relatively high-protein, low-lipid, and low-cholesterol contents. Palmitic acid and docosahexaenoic acid were the dominant saturated and polyunsaturated fatty acids, respectively, in both species. Amino acid compositions of adductor muscle from both species were characterized by a high abundance of glutamic acid, aspartic acid, and arginine, whereas cysteine, then tryptophan, were least abundant. Overall, these nutrient compositions are similar to those reported for other bivalve molluscs. The results are timely given the growing interest in pearl meat consumption and pearl meat farming. KEY WORDS: Pearl oyster meat, proximate composition, fatty acids, amino acids, aquaculture, Pinctada maxima, Pinctada margaritifera, INTRODUCTION Pearl oysters from the families Pteriidae and Margaritidae are harvested for food and used for cultured pearl production throughout the Indo-Pacific and Caribbean (Wada & Temkin 2008, Saucedo et [...]

Author(s): Pat Thane [sup.1] Author Affiliations: (1) https://ror.org/02mb95055, grid.88379.3d, 0000 0001 2324 0507, Birkbeck College, , London, UK Jon Cruddas' book commemorates a hundred years since the first Labour government [...]

Author(s): Patricia Thane [sup.1] Author Affiliations: (1) grid.88379.3d, 0000 0001 2324 0507, Birkbeck College London, , London, UK This is a very detailed survey of the weaknesses and failures of [...]

Author(s): Pat Thane [sup.1] Author Affiliations: (1) grid.88379.3d, 0000 0001 2324 0507, Birkbeck, University of London, , London, UK This is a detailed study of the extraordinary activities of the [...]

Amino acids are essential building blocks of life. However, increasing evidence suggests that elevated amino acids cause cellular toxicity associated with numerous metabolic disorders. How cells cope with elevated amino acids remains poorly understood. Here, we show that a previously identified cellular structure, the mitochondrial-derived compartment (MDC), functions to protect cells from amino acid stress. In response to amino acid elevation, MDCs are generated from mitochondria, where they selectively sequester and deplete SLC25A nutrient carriers and their associated import receptor Tom70 from the organelle. Generation of MDCs promotes amino acid catabolism, and their formation occurs simultaneously with transporter removal at the plasma membrane via the multivesicular body (MVB) pathway. The combined loss of vacuolar amino acid storage, MVBs, and MDCs renders cells sensitive to high amino acid stress. Thus, we propose that MDCs operate as part of a coordinated cell network that facilitates amino acid homeostasis through post-translational nutrient transporter remodeling.

Palau is a Pacific Island country that has a population of [approximately equal to] 17,500 persons (1). This country has a small health system, remote location, and high prevalence of [...]

The development of methods to reuse large volumes of plastic waste is essential to curb the environmental impact of plastic pollution. Plastic-reinforced cementitious materials (PRCs), such as plastic-reinforced mortar (PRM), may be potential avenues to productively use large quantities of low-value plastic waste. However, poor bonding between the plastic and cement matrix reduces the strength of PRCs, limiting its viable applications. In this study, calcium carbonate biomineralization techniques were applied to coat plastic waste and improved the compressive strength of PRM. Two biomineralization treatments were examined: enzymatically induced calcium carbonate precipitation (EICP) and microbially induced calcium carbonate precipitation (MICP). MICP treatment of polyethylene terephthalate (PET) resulted in PRMs with compressive strengths similar to that of plastic-free mortar and higher than the compressive strengths of PRMs with untreated or EICP-treated PET. Based on the results of this study, MICP was used to treat hard-to-recycle types 3-7 plastic waste. No plastics investigated in this study inhibited the MICP process. PRM samples with 5% MICP-treated polyvinyl chloride (PVC) and mixed type 3-7 plastic had compressive strengths similar to plastic-free mortar. These results indicate that MICP treatment can improve PRM strength and that MICP-treated PRM shows promise as a method to reuse plastic waste.

Author(s): Pat Thane [sup.1] Author Affiliations: (1) grid.4464.2, 0000 0001 2161 2573, University of London, , London, UK This volume celebrates the bicentenary in 2023 of what is now known [...]

There is considerable interest in developing hatchery techniques for the tropical spiny lobster, Panulirus ornatus. Although some progress has been made toward identifying effective foods and feeding protocols for this species, the density at which food is first provided to larvae varies greatly in practice. This study examined relationships between food density and the activities of major digestive enzymes in P. ornatus to evaluate larval feeding protocols from a nutrient utilization perspective. Specifically, activities of [alpha]-amylase. nonspecific esterase, and trypsin-like protease were quantified to determine the response of newly hatched larvae of P. ornatus to provision of Anemia nauplii at three different densities. Results showed that food density significantly (P < 0.01) influenced [alpha]-amylase and nonspecific esterase activities during the first 24 h of feeding, but had minimal effect (P [greater than or equal to] 0.09) on trypsin-like protease activities. Based on enzyme activities, there is no advantage to increasing food densities above 2.5 Anemia m[L.sup.-1], but when food density decreased to 0.5 Anemia m[L.sup.-1], the availability of dietary nutrients became limiting. An optimal density at which to provide Anemia nauplii to newly hatched larvae of P. ornatus is likely between 0.5 and 2.5 Anemia m[L.sup.-1]. The comparative analyses of enzyme activities presented in this study represents an innovative approach to identify potentially excessive or insufficient food densities quickly (within 24 h) for larval crustaceans. KEY WORDS: Panulirus ornatus. palinuridae. phyllosoma. hatchery, first-feeding, food ration, enzymology, INTRODUCTION There is considerable interest in developing reliable hatchery techniques for spiny lobsters (Palinuridae) driven by premium market value, high demand, and static or decreasing supply from wild-capture fisheries (Phillips [...]

The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as 'type material', thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity.

Author(s): Pat Thane [sup.1] Author Affiliations: (1) grid.88379.3d, 0000 0001 2324 0507, Department of History, Birkbeck College London, , London, UK The theme of this book is that Clement Attlee [...]