<i>Triebelina ? pustulata</i> Keij, 1974 from the Maldive Islands: more homeomorphy in the ornate Bairiidae (Ostracoda)

The male anatomy of Triebelina ? pustulata Keij, 1974 suggests affinities to Paranesidea rather than to Triebelina. It appears that as many as six lineages may have produced ornate reefal Bairdiidae: Glyptobairdia, Triebelina, Mydionobairdia, Havanardia, Pterobairdia and Triebelina ? pustulata and related species

Exclusion of maltodextrins from phosphatidylcholine multilayers during dehydration: effects on membrane phase behaviour

The effect of increasing solute size on phosphatidylcholine phase behaviour at a range of hydrations was investigated using differential scanning calorimetry. Dehydration of phospholipid membranes gives rise to a compressive stress within the bilayers that promotes fluid-to-gel phase transitions. According to the Hydration Forces Explanation, sugars in the intermembrane space minimize the compressive stress and limit increases in the fluid-gel transition temperature, Tm, by acting as osmotic and volumetric spacers that hinder the close approach of membranes. However, the sugars must remain between the bilayers in order to limit the rise in Tm. Large polymers are excluded from the interlamellar space during dehydration and do not limit the dehydration-induced rise in Tm. In this study, we used maltodextrins with a range of molecular weights to investigate the size-exclusion limit for polymers between phosphatidylcholine bilayers. Solutes with sizes ranging from glucose to dextran 1000 limited the rise in lipid Tm during dehydration, suggesting that they remain between dehydrated bilayers. At the lowest hydrations the solutions vitrified, and Tm was further depressed to about 20 °C below the transition temperature for the lipid in excess water, To. The depression of Tm below To occurs when the interlamellar solution vitrifies between fluid phase bilayers. The larger maltodextrins, dextran 5000 and 12,000, had little effect on the Tm of the PCs at any hydration, nor did vitrification of these larger polymers affect the lipid phase behaviour. This suggests that the larger maltodextrins are excluded from the interlamellar region during dehydration

Conformational analysis of nucleic acids revisited: Curves+

We describe Curves+, a new nucleic acid conformational analysis program which is applicable to a wide range of nucleic acid structures, including those with up to four strands and with either canonical or modified bases and backbones. The program is algorithmically simpler and computationally much faster than the earlier Curves approach, although it still provides both helical and backbone parameters, including a curvilinear axis and parameters relating the position of the bases to this axis. It additionally provides a full analysis of groove widths and depths. Curves+ can also be used to analyse molecular dynamics trajectories. With the help of the accompanying program Canal, it is possible to produce a variety of graphical output including parameter variations along a given structure and time series or histograms of parameter variations during dynamic

One-carbon metabolism in cancer

Cells require one-carbon units for nucleotide synthesis, methylation and reductive metabolism, and these pathways support the high proliferative rate of cancer cells. As such, anti-folates, drugs that target one-carbon metabolism, have long been used in the treatment of cancer. Amino acids, such as serine are a major one-carbon source, and cancer cells are particularly susceptible to deprivation of one-carbon units by serine restriction or inhibition of de novo serine synthesis. Recent work has also begun to decipher the specific pathways and sub-cellular compartments that are important for one-carbon metabolism in cancer cells. In this review we summarise the historical understanding of one-carbon metabolism in cancer, describe the recent findings regarding the generation and usage of one-carbon units and explore possible future therapeutics that could exploit the dependency of cancer cells on one-carbon metabolism

Investigating Hastily-Formed Collaborative Networks

This research explores both the human and technical aspects of the network centric environment in the context of a major disaster or incident of national significance. The National Incident Management System (NIMS) is viewed by the authors as a social network, and an organizational topology is developed to improve its effectiveness. A rapid Network Deployment Kit (RNDK) using commercial off the shelf (COTS) wireless networking technology is also proposed that facilitates immediate NIMS implementation. The integration of logical and technical analyses forms a comprehensive systems engineering proposal to facilitate collaboration in a net-centric environment. It is envisioned that the methodology used herein to derive and evaluate comprehensive networks proves extendable to other contexts thereby contributing to the netcentric body of knowledge

COVID-19: guidance on palliative care from a European Respiratory Society international task force

Copyright ©ERS 2020. BACKGROUND: Many people are dying from coronavirus disease 2019 (COVID-19), but consensus guidance on palliative care in COVID-19 is lacking. This new life-threatening disease has put healthcare systems under pressure, with the increased need of palliative care provided to many patients by clinicians who have limited prior experience in this field. Therefore, we aimed to make consensus recommendations for palliative care for patients with COVID-19 using the Convergence of Opinion on Recommendations and Evidence (CORE) process. METHODS: We invited 90 international experts to complete an online survey including stating their agreement, or not, with 14 potential recommendations. At least 70% agreement on directionality was needed to provide consensus recommendations. If consensus was not achieved on the first round, a second round was conducted. RESULTS: 68 (75.6%) experts responded in the first round. Most participants were experts in palliative care, respiratory medicine or critical care medicine. In the first round, consensus was achieved on 13 recommendations based upon indirect evidence and clinical experience. In the second round, 58 (85.3%) out of 68 of the first-round experts responded, resulting in consensus for the 14th recommendation. CONCLUSION: This multi-national task force provides consensus recommendations for palliative care for patients with COVID-19 concerning: advance care planning; (pharmacological) palliative treatment of breathlessness; clinician-patient communication; remote clinician-family communication; palliative care involvement in patients with serious COVID-19; spiritual care; psychosocial care; and bereavement care. Future studies are needed to generate empirical evidence for these recommendations

Plasmonic excitations in noble metals: The case of Ag

The delicate interplay between plasmonic excitations and interband transitions in noble metals is described by means of {\it ab initio} calculations and a simple model in which the conduction electron plasmon is coupled to the continuum of electron-hole pairs. Band structure effects, specially the energy at which the excitation of the $d$-like bands takes place, determine the existence of a subthreshold plasmonic mode, which manifests itself in Ag as a sharp resonance at 3.8 eV. However, such a resonance is not observed in the other noble metals. Here, this different behavior is also analyzed and an explanation is provided.Comment: 9 pages, 8 figure

Plasmon Lifetime in K: A Case Study of Correlated Electrons in Solids Amenable to Ab Initio Theory

On the basis of a new ab initio, all-electron response scheme, formulated within time-dependent density-functional theory, we solve the puzzle posed by the anomalous dispersion of the plasmon linewidth in K. The key damping mechanism is shown to be decay into particle-hole pairs involving empty states of d-symmetry. While the effect of many-particle correlations is small, the correlations built into the "final-state" -d-bands play an important, and novel, role ---which is related to the phase-space complexity associated with these flat bands. Our case study of plasmon lifetime in K illustrates the importance of ab initio paradigms for the study of excitations in correlated-electron systems.Comment: 12 pages, 4 figures, for html browsing see http://web.utk.edu/~weik

An assessment of the strength of knots and splices used as eye terminations in a sailing environment

Research into knots, splices and other methods of forming an eye termination has been limited, despite the fact that they are essential and strongly affect the performance of a rope. The aim of this study was to carry out a comprehensive initial assessment of the breaking strength of eye terminations commonly used in a sailing environment, thereby providing direction for further work in the field. Supports for use in a regular tensile testing machine were specially developed to allow individual testing of each sample and a realistic spread of statistical data to be obtained. Over 180 break tests were carried out on four knots (the bowline, double bowline, figure-of-eight loop and perfection loop) and two splices (three-strand eye splice and braid-on-braid splice). The factors affecting their strength were investigated. A statistical approach to the analysis of the results was adopted. The type of knot was found to have a significant effect on the strength. This same effect was seen in both types of rope construction (three-strand and braid-on-braid). Conclusions were also drawn as to the effect of splice length, eye size, manufacturer and rope diameter on the breaking strength of splices. Areas of development and further investigation were identified

On the nonlinear stability of mKdV breathers

A mathematical proof for the stability of mKdV breathers is announced. This proof involves the existence of a nonlinear equation satisfied by all breather profiles, and a new Lyapunov functional which controls the dynamics of small perturbations and instability modes. In order to construct such a functional, we work in a subspace of the energy one. However, our proof introduces new ideas in order to attack the corresponding stability problem in the energy space. Some remarks about the sine-Gordon case are also considered.Comment: 7 p