Dynamics of BPS States in the Dirac-Born-Infeld Theory

The Dirac-Born-Infeld action with transverse scalar fields is considered to study the dynamics of various BPS states. We first describe the characteristic properties of the so-called 1/2 and 1/4 BPS states on the D3 brane, which can be interpreted as F/D-strings ending on a D3-brane in Type IIB string theory picture. We then study the response of the BPS states to low energy excitations of massless fields on the brane, the scalar fields representing the shape fluctuation of the brane and U(1) gauge fields describing the open string excitations on the D-brane. This leads to an identification of interactions between BPS states including the static potentials and the kinetic interactions.Comment: 19 pages, 4 figures References added, Typographical errors are correcte

Correction : A global overview of the genetic and functional diversity in the helicobacter pylori cag pathogenicity island

The Helicobacter pylori cag pathogenicity island (cagPAI) encodes a type IV secretion system. Humans infected with cagPAI–carrying H. pylori are at increased risk for sequelae such as gastric cancer. Housekeeping genes in H. pylori show considerable genetic diversity; but the diversity of virulence factors such as the cagPAI, which transports the bacterial oncogene CagA into host cells, has not been systematically investigated. Here we compared the complete cagPAI sequences for 38 representative isolates from all known H. pylori biogeographic populations. Their gene content and gene order were highly conserved. The phylogeny of most cagPAI genes was similar to that of housekeeping genes, indicating that the cagPAI was probably acquired only once by H. pylori, and its genetic diversity reflects the isolation by distance that has shaped this bacterial species since modern humans migrated out of Africa. Most isolates induced IL-8 release in gastric epithelial cells, indicating that the function of the Cag secretion system has been conserved despite some genetic rearrangements. More than one third of cagPAI genes, in particular those encoding cell-surface exposed proteins, showed signatures of diversifying (Darwinian) selection at more than 5% of codons. Several unknown gene products predicted to be under Darwinian selection are also likely to be secreted proteins (e.g. HP0522, HP0535). One of these, HP0535, is predicted to code for either a new secreted candidate effector protein or a protein which interacts with CagA because it contains two genetic lineages, similar to cagA. Our study provides a resource that can guide future research on the biological roles and host interactions of cagPAI proteins, including several whose function is still unknown

“Electronic nose” signals correlation evaluation for nasal mucus and exhaled breath condensate of calves with the clinical and laboratory indicators

Submitted 18 November 2019, received in revised form 2 December 2019Поступила в редакцию 18 ноября 2019 г., после исправления 2 декабря 2019 г.In this article the “electronic nose” system (SNT LLC, Russia) with an array of 8 differently selective piezoelectric sensors (nanobio array) was used to assess the health and functioning of the respiratory organs in young cattle by the fraction of volatile compounds over bioassays (exhaled breath condensate and nasal mucus). The sorption of the volatile fraction of substances vapors from the two types of bioassays was studied for 80s with the frontal effortless injection of vapors into the near-sensor space of the detection cell of the “electronic nose” at 20 ± 1 .C with the subsequent fixation of the spontaneous desorption for 120s -total measurement time 200s . The simplest analytical signals of the “electronic nose” (S. и S neg) recorded and calculated in the software for the samples were proposed suitable for assessing the health of the respiratory organs in calves. A significant correlation was found between the analytical signals of the “electronic nose” and the established informative indicators of bovine respiratory diseases: increased activity of aspartate aminotransferase, alanine aminotransferase, creatinine in samples of exhaled breath condensate, respiratory failure index, and leukocyte count. The samples of nasal mucus were better used for the health assessment of the respiratory system using the nanobio array of sensors. Despite the initial small number of samples, the approach is universal and could be extended to the studies of other animals.Обсуждается взаимосвязь первичных выходных данных массива сенсоров (площади мно­гомерных аналитических сигналов сенсоров – «визуальных отпечатков») в парах биопроб телят (носовая слизь, конденсат выдыхаемого воздуха) с клиническими и лабораторными показателями, связанными с воспалением или наличием возбудителей инфекций, сопровождающим поражение органов дыхания животных. Установлено, что многомерные аналитические сигналы массива сенсоров для разных видов биопроб не коррелируют между собой, но по показателю доли трудно десорбирующихся веществ (кислоты, разветвленные алифатические, циклические амины) в общей смеси легколетучих соединений положительно оценена возможность замены проб конденсата выдыхаемого воздуха на пробы носовой слизи, которая отбирается быстро и менее травматично, для мониторинга состояния здоровья верхних дыхательных путей молодняка крупного рогатого скота. Установлена статистически значимая корреляция между откликами массива сенсоров для проб носовой слизи и биохимическими показателями повреждения клеток респираторного тракта в конденсате выдыхаемого воздуха (активность аспартатаминотрансферазы, аланинаминотрансферазы и концентрация креатинина), индексом дыхательной недостаточности, содержанием лейкоцитов в крови. Отклики сенсоров для проб носовой слизи являются более информативными для ранней диагностики респираторных заболеваний у телят.This work was financially supported by the Russian Science Foundation (grant number 18-76-10015).Работа выполнена при финансовой поддержке гранта РНФ № 18-76-10015