Exotic solutions in string theory

Solutions of classical string theory, correspondent to the world sheets, mapped in Minkowsky space with a fold, are considered. Typical processes for them are creation of strings from vacuum, their recombination and annihilation. These solutions violate positiveness of square of mass and Regge condition. In quantum string theory these solutions correspond to physical states |DDF>+|sp> with non-zero spurious component.Comment: accepted in Il Nuovo Cimento A for publication in 199

Impact of Plant-Based Meat Alternatives on the Gut Microbiota of Consumers: A Real-World Study

Eating less meat is increasingly seen as a healthier, more ethical option. This is leading to growing numbers of flexitarian consumers looking for plant-based meat alternatives (PBMAs) to replace at least some of the animal meat they consume. Popular PBMA products amongst flexitarians, including plant-based mince, burgers, sausages and meatballs, are often perceived as low-quality, ultra-processed foods. However, we argue that the mere industrial processing of ingredients of plant origin does not make a PBMA product ultra-processed by default. To test our hypothesis, we conducted a randomised controlled trial to assess the changes to the gut microbiota of a group of 20 participants who replaced several meat-containing meals per week with meals cooked with PBMA products and compared these changes to those experienced by a size-matched control. Stool samples were subjected to 16S rRNA sequencing. The resulting raw data was analysed in a compositionality-aware manner, using a range of innovative bioinformatic methods. Noteworthy changes included an increase in butyrate metabolising potential—chiefly in the 4-aminobutyrate/succinate and glutarate pathways—and in the joint abundance of butyrate-producing taxa in the intervention group compared to control. We also observed a decrease in the Tenericutes phylum in the intervention group and an increase in the control group. Based on our findings, we concluded that the occasional replacement of animal meat with PBMA products seen in flexitarian dietary patterns can promote positive changes in the gut microbiome of consumers

Validation-free offchain transactions with unlinkable double spend detection

The so-called layer-two protocols are a class of blockchain scaling solutions. They allow to minimize onchain traffic, and therefore make state transitions (payments, for example) faster and more suitable for everyday use, while still preventing double spend attacks. Unfortunately, these solutions also have some downsides and tradeoffs (channel capacity, route availability, operator availability, etc.). In this work we study the possibility of simplifying and improving existing protocols for offchain transactions and describe a scheme that, without transaction validation, allows to detect a double The so-called layer-two protocols are a class of blockchain scaling solutions. They allow to minimize onchain traffic, and therefore make state transitions (payments, for example) faster and more suitable for everyday use, while still preventing double spend attacks. Unfortunately, these solutions also have some downsides and tradeoffs (channel capacity, route availability, operator availability, etc.). In this work we study the possibility of simplifying and improving existing protocols for offchain transactions and describe a scheme that, without transaction validation, allows to detect a doubl

A new look at the modified Coulomb potential in a strong magnetic field

The static Coulomb potential of Quantum Electrodynamics (QED) is calculated in the presence of a strong magnetic field in the lowest Landau level (LLL) approximation using two different methods. First, the vacuum expectation value of the corresponding Wilson loop is calculated perturbatively in two different regimes of dynamical mass $m_{dyn.}$, {\it i.e.}, $|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$ and $m_{dyn.}^{2}\ll |\mathbf{q}_{\|}^{2}|\ll|eB|$, where $\mathbf{q}_{\|}$ is the longitudinal components of the momentum relative to the external magnetic field $B$. The result is then compared with the static potential arising from Born approximation. Both results coincide. Although the arising potentials show different behavior in the aforementioned regimes, a novel dependence on the angle $\theta$ between the particle-antiparticle's axis and the direction of the magnetic field is observed. In the regime $|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$, for strong enough magnetic field and depending on the angle $\theta$, a qualitative change occurs in the Coulomb-like potential; Whereas for $\theta=0,\pi$ the potential is repulsive, it exhibits a minimum for angles $\theta\in]0,\pi[$.Comment: V1: 26 pages, 8 figures, latex format, V2: Accepted for publication in PRD (2007

Cold diffuse interstellar medium of Magellanic Clouds: II. Physical conditions from excitation of CI and H2_2

We present a comprehensive study of the excitation of CI fine-structure levels along 57 sight lines in the Large and Small Magellanic Clouds. The sight lines were selected by the detection of H$_2$ in FUSE spectra. Using archival HST/COS and HST/STIS spectra we detected absorption of CI fine-structure levels and measured their populations for 29 and 22 sight lines in the LMC and SMC, respectively. The CI column density ranges from $10^{13}$ to $10^{14}\,{\rm cm}^{-2}$ for the LMC and $10^{13}$ to $10^{15.4}\,{\rm cm}^{-2}$ for the SMC. We found excitation of CI fine-structure levels in the LMC and SMC to be 2-3 times higher than typical values in local diffuse ISM. Comparing excitation of both CI fine-structure levels and H$_2$ rotational levels with a grid of PDR Meudon models we find that neutral cold gas in the LMC and SMC is illuminated by stronger UV field than in local ISM ($\chi=5^{+7}_{-3}$ units of Mathis field for the LMC and $2^{+4}_{-1}$ for the SMC) and has on average higher thermal pressure ($\log p/k =4.2\pm0.4$ and $4.3\pm0.5$, respectively). Magellanic Clouds sight lines likely probe region near star-formation sites, which also affects the thermal state and CI/H$_2$ relative abundances. At the same time such high measurements of UV field are consistent with some values obtained at high redshifts. Together with low metallicities this make Magellanic Clouds to be an interesting test case to study of the central parts of high redshift galaxies.Comment: submitted to MNRA

Formation of a pentagonal particle structure from copper nanoclusters

The structure of pentagonal particles and the processes of their formation from nanoclusters with the fifthorder symmetry axes are investigated by the methods of computer modeling and scanning electron-ion microscopy using copper as an example. It is demonstrated that the mechanism of cluster growth to pentagonal particles can be realized at which the volumetric stress present in noncrystal clusters will be released without breaking of the fifth-order symmetry of the growing cluster shapeye

HIP AND BUTTOCKS PAIN SYNDROME — LOOK OF THE INTERNIST

Differential approach to the diagnosis of diseases associated with pain in the hips and buttocks is presented in this lecture