An Evaluation of the Possible Protective Effects of Neonatal Striatal Transplants Against Kainic Acid-Induced Lesions

The present study examined the recent report that transplantation of neonatal striatal tissue into kainic acid (KA) lesioned striatum protected the contralateral striatum from a subsequent KA lesion. We did not find a significant difference in the survival rate of animals that received neonatal striatal transplants into a KA lesioned striatum followed by a subsequent lesion of the contralateral striatum compared to those animals that received bilateral KA-induced striatal lesions alone. The tissue transplants did not protect against the degeneration of striatal neurons induced by KA. Indeed, the survival rate was very low (25%) in the transplant groups. A second experiment was also performed to examine whether a neonatal striatal transplant might reduce the severe syndrome of aphagia and adipsia associated with KA lesions of the striatum. Animals that received the neonatal striatal transplants showed increased aphagia and adipsia compared to animals only receiving the KA lesion. Again, the transplant group had a very low survival rate (10%). The present study was unable to confirm that neonatal striatal transplants protect against KA lesions either by themselves or in conjunction with a recent KA lesion

Feasibility of Infectious Prion Digestion Using Mild Conditions and Commercial Subtilisin

Two serine protease enzymes, subtilisin 309 and subtilisin 309-v,were used to digest brain homogenates containing high levels of prion infectivity using mildly alkaline conditions to investigate prion decontamination methods. To establish that PrPres infectivity was eliminated, we utilized the Rocky Mountain Laboratory (RML) mouse-adapted scrapie model system for bioassay. Only one digestion condition (subtilisin 309 at 138mAU/ml, 55 ◦C and 14 h digestion time pH 7.9) was considered to be highly relevant statistically (P \u3c 0.001) compared to control, with 52% of challenged mice surviving until the end of the study period. In contrast, treatment of PrPres by autoclaving at 134 ◦C or treatment with hypochlorite at a concentration of 20,000ppm completely protected mice from prionosis. Further, in vitro assays suggest that potential proteolytic based PrPres decontamination methods must use high enzyme concentration, pH values \u3e9.0, and elevated temperatures to be a safely efficacious, thereby limiting applicability on delicate surgical instruments and use in the environment

Demand driven salt clean-up in a molten salt fast reactor – Defining a priority list

<div><p>The PUREX technology based on aqueous processes is currently the leading reprocessing technology in nuclear energy systems. It seems to be the most developed and established process for light water reactor fuel and the use of solid fuel. However, demand driven development of the nuclear system opens the way to liquid fuelled reactors, and disruptive technology development through the application of an integrated fuel cycle with a direct link to reactor operation. The possibilities of this new concept for innovative reprocessing technology development are analysed, the boundary conditions are discussed, and the economic as well as the neutron physical optimization parameters of the process are elucidated. Reactor physical knowledge of the influence of different elements on the neutron economy of the reactor is required. Using an innovative study approach, an element priority list for the salt clean-up is developed, which indicates that separation of Neodymium and Caesium is desirable, as they contribute almost 50% to the loss of criticality. Separating Zirconium and Samarium in addition from the fuel salt would remove nearly 80% of the loss of criticality due to fission products. The theoretical study is followed by a qualitative discussion of the different, demand driven optimization strategies which could satisfy the conflicting interests of sustainable reactor operation, efficient chemical processing for the salt clean-up, and the related economic as well as chemical engineering consequences. A new, innovative approach of balancing the throughput through salt processing based on a low number of separation process steps is developed. Next steps for the development of an economically viable salt clean-up process are identified.</p></div

The evolution of embryonic creek systems in a recently inundated large open coast managed realignment site

Managed realignment (MR) schemes are being implemented to compensate for the degradation of coastal habitats. However, evidence suggests that MR sites have lower biodiversity than anticipated, which has been linked to poor drainage. Despite creek networks playing an important role in enhancing site drainage in natural intertidal environments, there remains a shortage of data on the formation and evolution of creeks within MR sites. This study evaluates creek development at the Medmerry Managed Realignment Site, UK. Creek development is investigated using differential global positioning system(dGPS) data, supported by sedimentological analyses and a high-resolution digital surface model (DSM) derived from images taken using a small unmanned aerial vehicle. Measurements indicated that creeks will develop relatively quickly, but are influenced by differences in the sub-surface sedimentological conditions. A suitable level of agreement was found between the DSM and dGPS measurements, demonstrating the appropriateness of this method to study creek development within intertidal environments at a higher resolution than traditional surveying techniques. These results are used to propose the collapseof sub-surface piping as the primary creek formation mechanism. Findings are discussed in terms of increasing the success of MR schemes and enhancing site design to maximise the ecosystem services provided

Direct observations of the kinetics of migrating T-cells suggest active retention by endothelial cells with continual bidirectional migration.

The kinetics and regulatory mechanisms of T-cell migration through endothelium have not been fully defined. In experimental filter-based assays in vitro, transmigration of lymphocytes takes hours, compared to minutes in vivo. We cultured endothelial cell (EC) monolayers on filters, solid substrates or collagen gels, and treated them with tumour necrosis factor-α (TNF), interferon-γ (IFN), or both, prior to analysis of lymphocyte migration in the presence or absence of flow. Peripheral blood lymphocytes (PBL), CD4+ cells or CD8+ cells, took many hours to migrate through EC-filter constructs for all cytokine treatments. However, direct microscopic observations of EC-filters which had been mounted in a flow chamber showed that PBL crossed the endothelial monolayer in minutes and were highly motile in the subendothelial space. Migration through EC was also observed on clear plastic, with or without flow. After brief settling without flow, PBL and isolated CD3+ or CD4+ cells all crossed EC in minutes, but the numbers of migrated cells varied little with time. Close observation revealed that lymphocytes continuously migrated back and forth across endothelium. Under flow, migration kinetics and the proportions migrating back and forth were little altered. On collagen gels, PBL again crossed EC in minutes and migrated back and forth, but showed little penetration of the gel over hours.In contrast, neutrophils migrated efficiently through EC and into gels. These observations suggest a novel model for lymphoid migration, in which endothelial cells support migration but retain lymphocytes (as opposed to neutrophils), and additional signal(s) are required for onward migration

Predation by <i>Corallus annulatus</i> (Boidae) on <i>Rhynchonycteris naso</i> (Emballonuridae) in a lowland tropical wet forest, Costa Rica

Corallus annulatus (Northern Annulated Tree-boa) is a little-studied tropical Boid occurring disjunctively throughout Central America and tropical South America in mostly lowland tropical moist and wet forests (Holdridge, 1967; Stafford & Henderson, 1996; Smith & Acevedo, 1997; Henderson et al., 2001). Prior to this report and to the best of our knowledge, small rodents were the only documented prey for wild specimens of C. annulatus (Henderson et al., 1995). Caño Palma Biological Station is situated on the northeast coast of Costa Rica approximately 8 km north of Tortuguero. C. annulatus has previously been recorded from Manicaria forest at Caño Palma (Myers, 1990; Burger, 2001). On 12th January 2002 and 15th July 2003 we found two separate C. annulatus specimens with Rhynchonycteris naso (Proboscis bat) in their stomachs.Asociación Herpetológica Argentina (AHA

Cross-linkers both drive and brake cytoskeletal remodeling and furrowing in cytokinesis.

Cell shape changes such as cytokinesis are driven by the actomyosin contractile cytoskeleton. The molecular rearrangements that bring about contractility in nonmuscle cells are currently debated. Specifically, both filament sliding by myosin motors, as well as cytoskeletal cross-linking by myosins and nonmotor cross-linkers, are thought to promote contractility. Here we examined how the abundance of motor and nonmotor cross-linkers affects the speed of cytokinetic furrowing. We built a minimal model to simulate contractile dynamics in the Caenorhabditis elegans zygote cytokinetic ring. This model predicted that intermediate levels of nonmotor cross-linkers are ideal for contractility; in vivo, intermediate levels of the scaffold protein anillin allowed maximal contraction speed. Our model also demonstrated a nonlinear relationship between the abundance of motor ensembles and contraction speed. In vivo, thorough depletion of nonmuscle myosin II delayed furrow initiation, slowed F-actin alignment, and reduced maximum contraction speed, but partial depletion allowed faster-than-expected kinetics. Thus, cytokinetic ring closure is promoted by moderate levels of both motor and nonmotor cross-linkers but attenuated by an over-abundance of motor and nonmotor cross-linkers. Together, our findings extend the growing appreciation for the roles of cross-linkers in cytokinesis and reveal that they not only drive but also brake cytoskeletal remodeling

The use of a length-structured multispecies model fitted directly to data in near-real time as a viable tool for advice

Fish communities are multispecies assemblages, so ideally multispecies models should be used directly for assessing this resource. However, progress in this direction has been slow, partly because these models are often more complex and take longer to fit, rendering them too slow to demonstrate near-real-time utility, and thus creating a perception that they are opaque to stakeholders. In this study we implemented a multispecies assessment for the Irish Sea, fitting a model of eight key stocks directly to catch and survey data. Two novel features of our approach allowed the multispecies model to be fitted within a few hours. Firstly, by using size-based theory and life-history invariants to specify many of the required properties of stocks, we reduced the number of general parameters that needed to be fitted directly to a more manageable 25. Secondly, by using state-of-the-art fitting methods, we found acceptable solutions quickly enough to provide assessments within the timescale of an advisory meeting. The outcomes were compared with the standard single species assessments of the same eight species. Model fits were generally good for either catch or at least one of the surveys, but not for all data sources at the same time, illustrating the challenges of fitting multiple stocks to different data sources simultaneously. Estimates of SSB and F agreed qualitatively with the assessments for most stocks with the exception of whiting. Estimates of natural mortality showed modest year to year variability, suggesting that single species assessments may be appropriate for short term tactical management. This method shows great promise for making multispecies assessments as a complement to existing assessments because of the rapid turnaround time and ability to respond at meetings to the requests of stakeholders. In addition, because these models avoid our current dependence on existing single species models they can be used to provide boundary conditions in natural mortality for standard assessment models and check for internal consistency in the assessment process. Furthermore, they are easily accessible because they are based upon freely available code

Science exploration opportunities for manned missions to the Moon, Mars, Phobos, and an asteroid

Scientific exploration opportunities for human missions to the Moon, Phobos, Mars, and an asteroid are addressed. These planetary objects are of prime interest to scientists because they are the accessible, terresterial-like bodies most likely to be the next destinations for human missions beyond Earth orbit. Three categories of science opportunities are defined and discussed: target science, platform science, and cruise science. Target science is the study of the planetary object and its surroundings (including geological, biological, atmospheric, and fields and particle sciences) to determine the object's natural physical characteristics, planetological history, mode of origin, relation to possible extant or extinct like forms, surface environmental properties, resource potential, and suitability for human bases or outposts. Platform science takes advantage of the target body using it as a site for establishing laboratory facilities and observatories; and cruise science consists of studies conducted by the crew during the voyage to and from a target body. Generic and specific science opportunities for each target are summarized along with listings of strawman payloads, desired or required precursor information, priorities for initial scientific objectives, and candidate landing sites. An appendix details the potential use of the Moon for astronomical observatories and specialized observatories, and a bibliography compiles recent work on topics relating to human scientific exploration of the Moon, Phobos, Mars, and asteroids. It is concluded that there are a wide variety of scientific exploration opportunities that can be pursued during human missions to planetary targets but that more detailed studies and precursor unmanned missions should be carried out first

Commentary: Combining ecosystem and single-species modeling to provide ecosystem-based fisheries management advice within current management systems

A Commentary on: 'Combining Ecosystem and Single-Species Modeling to Provide Ecosystem-Based Fisheries Management Advice Within Current Management Systems' by Howell, D., Schueller, A. M., Bentley, J. W., Buchheister, A., Chagaris, D., Cieri, M., Drew, K., Lundy, M. G., Pedreschi, D., Reid, D. G., and Townsend, H. (2021). Front. Mar. Sci. 7:607831. doi: 10.3389/fmars.2020.60783