Selection strategy and the design of hybrid oligonucleotide primers for RACE-PCR: cloning a family of toxin-like sequences from Agelena orientalis

<p>Abstract</p> <p>Background</p> <p>the use of specific but partially degenerate primers for nucleic acid hybridisations and PCRs amplification of known or unknown gene families was first reported well over a decade ago and the technique has been used widely since then.</p> <p>Results</p> <p>here we report a novel and successful selection strategy for the design of hybrid partially degenerate primers for use with RT-PCR and RACE-PCR for the identification of unknown gene families. The technique (named PaBaLiS) has proven very effective as it allowed us to identify and clone a large group of mRNAs encoding neurotoxin-like polypeptide pools from the venom of <it>Agelena orientalis </it>species of spider. Our approach differs radically from the generally accepted CODEHOP principle first reported in 1998. Most importantly, our method has proven very efficient by performing better than an independently generated high throughput EST cloning programme. Our method yielded nearly 130 non-identical sequences from <it>Agelena orientalis</it>, whilst the EST cloning technique yielded only 48 non-identical sequences from 2100 clones obtained from the same <it>Agelena </it>material. In addition to the primer design approach reported here, which is almost universally applicable to any PCR cloning application, our results also indicate that venom of <it>Agelena orientalis </it>spider contains a much larger family of related toxin-like sequences than previously thought.</p> <p>Conclusion</p> <p>with upwards of 100,000 species of spider thought to exist, and a propensity for producing diverse peptide pools, many more peptides of pharmacological importance await discovery. We envisage that some of these peptides and their recombinant derivatives will provide a new range of tools for neuroscience research and could also facilitate the development of a new generation of analgesic drugs and insecticides.</p

Elusive exotic states

The existence of flavor exotic $QQ\bar{q}\bar{q}$ molecular-type states is investigated. An attractive force between two {\it pseudoscalar} $H = (Q\bar{q})$ heavy meson is generated by (correlated) two-pion exchange. The emergence of a (loosely) bound state depends crucially on the value of the coupling constant $g$ of the $H^*H\pi$ vertex. For a $g$ value calculated from the experimental upper limit on the width of the $D^*$ meson the considered mechanism alone is strong enough to generate a bound state in the $BB$ system while the $DD$ system is very close to become bound. Such states, if exist, are stable with respect to strong interactions. They may be observed as stable scalar particles with the mass $M\approx 2\,m_H$ and flavor quantum number $\pm 2$.Comment: 10 pages including 4 figures. RevTex and epsfig.sty are used. Accepted for publication in Phys. Lett.

Nonlinear superconformal symmetry of a fermion in the field of a Dirac monopole

We study a longstanding problem of identification of the fermion-monopole symmetries. We show that the integrals of motion of the system generate a nonlinear classical Z_2-graded Poisson, or quantum super- algebra, which may be treated as a nonlinear generalization of the $osp(2|2)\oplus su(2)$. In the nonlinear superalgebra, the shifted square of the full angular momentum plays the role of the central charge. Its square root is the even osp(2|2) spin generating the u(1) rotations of the supercharges. Classically, the central charge's square root has an odd counterpart whose quantum analog is, in fact, the same osp(2|2) spin operator. As an odd integral, the osp(2|2) spin generates a nonlinear supersymmetry of De Jonghe, Macfarlane, Peeters and van Holten, and may be identified as a grading operator of the nonlinear superconformal algebra.Comment: 13 pages; comments and ref added; V.3: misprints corrected, journal versio

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Визит Шарля де Голля в Советский Союз и вопросы внешнеполитической стратегии Москвы в 1966–1969 гг.

The article is based on recent archival findings that throw a new light on the preparations for and results of President Charles de Gaulle’s state visit to the USSR in 1966. The results are analysed as part of the expansion of Soviet bi- and multilateral relations which developed in the context of European cooperation in the late 1960s. Special emphasis is given to the unprecedented media support for Franco-Soviet contacts. Focus is placed on the preparation and organisation of the visit, with reference to new archival materials from the Russian State Archive of Contemporary History. The author also illustrates the Soviet authorities’ realistic and flexible approach to foreign affairs. It is also noted that, regardless of the social structure of European states, issues of economic and technical collaboration were the objects of a great deal of attention. This state visit is compared with the visits of other leaders, such as Richard Nixon, Harold Macmillan, and Konrad Adenauer, to the Soviet Union. The article demonstrates that Soviet diplomats and highly-ranked officials had a very special attitude towards de Gaulle even during his resignation in 1969. The ‘special relations’ between Moscow and Paris after de Gaulle’s visit could be considered as one of the best examples of peaceful convergence between the West and the East in the 1960s.На новом архивном материале рассмотрены обстоятельства визита президента Французской Республики Шарля де Голля в Советский Союз в 1966 г. и их значение для дальнейшего развития двусторонних и многосторонних отношений СССР в широком контексте политики общеевропейского сотрудничества второй половины 1960-х гг. Показан беспрецедентный для своего времени масштаб мер информационного сопровождения советско-французских контактов. Особое внимание уделено изучению подготовки и проведения данного визита на основе новых архивных материалов РГАНИ. Показаны реалистичность и гибкость внешнеполитического подхода руководства СССР. Отмечено важное значение вопросов экономического и научно-технического сотрудничества государств Европы вне зависимости от их социального строя, которым на переговорах было уделено самое пристальное внимание. Визит анализируется в сравнении с визитами в Советский Союз таких государственных деятелей как Гарольд Макмиллан, Ричард Никсон и Конрад Аденауэр. Автор приходит к выводу об особом отношении к персоне де Голля со стороны советских дипломатов и высшего партийного руководства даже в момент его от- ставки с президентского поста в 1969 г. и о важности советско-французских отношений в качестве эталона возможностей мирной конвергенции Запада и Востока в 1960-х гг

Peukert Generalized Equations Applicability with Due Consideration of Internal Resistance of Automotive-Grade Lithium-Ion Batteries for Their Capacity Evaluation

In this paper, the applicability of the Peukert equation and its generalizations were investigated for capacity evaluation of automotive-grade lithium-ion batteries. It is proved that the classical Peukert equation is applicable within the range of the discharge currents from 0.2Cn to 2Cn (Cn is the nominal battery capacity). As a rule, the operating currents of many automotive-grade lithium-ion batteries are exactly within this range of the discharge currents. That is why, successfully, the classical Peukert equation is used in many analytical models developed for these batteries. The generalized Peukert equation C = Cm/(1 + (i/i0)n) is applicable within the discharge currents range from zero to approximately 10Cn. All kinds of operating discharge currents (including both very small ones and powerful short-term bursts) fall into this discharge currents range. The modified Peukert equation C = Cm(1 − i/i1)/((1 − i/i1) + (i/i0)n) is applicable at any discharge currents. This equation takes into account the battery’s internal resistance and has the smallest error of experimental data approximation. That is why the discussed modified Peukert equation is most preferable for use in analytical models of automotive-grade lithium-ion batteries. The paper shows that all the parameters of the generalized Peukert equations have a clear electrochemical meaning in contrast to the classical Peukert equation, where all the parameters are just empirical constants

Analysis of Peukert Generalized Equations Use for Estimation of Remaining Capacity of Automotive-Grade Lithium-Ion Batteries

In this paper, it is shown that the Peukert generalized equations C = Cm/(1 + (i/i0)n), C = 0.522Cmtanh((i/i0)n/0.522)/(i/i0)n and C = Cmerfc((i/ik &minus; 1)/(1/n))/erfc(&minus;n) are applicable for capacity estimation of the automotive-grade lithium-ion batteries within the discharge current range, from 0 to 10 Cn. Additionally, it is shown here that all the parameters (Cm, n, i0 and ik) in the Peukert generalized equations under study have a clear physical meaning, unlike in the classical Peukert equation, in which all the parameters are just empirical constants. In addition, it is shown that, in the case of lithium-ion batteries, the dependence of their released capacity on the discharge current reflects the phase transition statistical pattern in the electrodes&rsquo; active substance, which follows the normal distribution law. As the Peukert equation is used in many analytical models, the better electrochemical and physical meaning and understanding of this equation and its clarification are of great practical importance

Analysis of Peukert Generalized Equations Use for Estimation of Remaining Capacity of Automotive-Grade Lithium-Ion Batteries

In this paper, it is shown that the Peukert generalized equations C = Cm/(1 + (i/i0)n), C = 0.522Cmtanh((i/i0)n/0.522)/(i/i0)n and C = Cmerfc((i/ik − 1)/(1/n))/erfc(−n) are applicable for capacity estimation of the automotive-grade lithium-ion batteries within the discharge current range, from 0 to 10 Cn. Additionally, it is shown here that all the parameters (Cm, n, i0 and ik) in the Peukert generalized equations under study have a clear physical meaning, unlike in the classical Peukert equation, in which all the parameters are just empirical constants. In addition, it is shown that, in the case of lithium-ion batteries, the dependence of their released capacity on the discharge current reflects the phase transition statistical pattern in the electrodes’ active substance, which follows the normal distribution law. As the Peukert equation is used in many analytical models, the better electrochemical and physical meaning and understanding of this equation and its clarification are of great practical importance

Research of Nanomaterials as Electrodes for Electrochemical Energy Storage

This paper has experimentally proved that hydrogen accumulates in large quantities in metal-ceramic and pocket electrodes of alkaline batteries during their operation. Hydrogen accumulates in the electrodes in an atomic form. After the release of hydrogen from the electrodes, a powerful exothermic reaction of atomic hydrogen recombination with a large energy release occurs. This exothermic reaction is the cause of thermal runaway in alkaline batteries. For the KSL-15 battery, the gravimetric capacity of sintered nickel matrix of the oxide-nickel electrode, as hydrogen storage, is 20.2 wt%, and cadmium electrode is 11.5 wt%. The stored energy density in the metal-ceramic matrix of the oxide-nickel electrode of the battery KSL-15 is 44 kJ/g, and in the cadmium electrode it is 25 kJ/g. The similar values for the KPL-14 battery are as follows. The gravimetric capacity of the active substance of the pocket oxide-nickel electrode, as a hydrogen storage, is 22 wt%, and the cadmium electrode is 16.9 wt%. The density of the stored energy in the active substance oxide-nickel electrode is 48 kJ/g, and in the active substance of the cadmium electrode it is 36.8 kJ/g. The obtained results of the accumulation of hydrogen energy in the electrodes by the electrochemical method are three times higher than any previously obtained results using the traditional thermochemical method