Using mosaic crystals for the generation of intense X-ray beams

The parametric X-ray (PXR) yield due to 500-MeV electrons in a 2-mm-thick diamond crystal with a mosaicity angle of ~0.2 mrad has been studied. It is shown that the mosaic crystal structure leads to a significant (about fourfold) increase in the PXR yield doe to the contribution of diffracted bremsstrahlung radiationye

Association of haplotypes for SNPs in the LTR regions of bovine leukemia virus with hematological indices of cattle

Molecular typing of BLV samples isolated from Holsteinized Russian Black Pied cattle was carried out, and various cytofluorometric and morphological blood indices were examined. We performed the total count of white blood cells (WBC), lymphocyte (lymf), granulocyte (gran), monocyte (mon), red blood cell (RBC), hemoglobin (HGB), hematocrit (HTC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width (RDW), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and platelet crit count (PCT). The LTR-region of BLV was haplotyped. Only viruses of haplotypes I (0.33±0.03) and III (0.67±0.03) of the eight possible were detected. The ratio of hematologically sick, healthy, and suspected carriers of BLV of haplotypes I and II was comparable with the results of other researchers. The numbers of leukocytes, erythrocytes and platelets in the blood of carriers of haplotype III exceeded the corresponding parameters of cattle affected by the virus of haplotype I. It is interesting to note that the difference in the hemolytic status of animals was manifested not only by the concentration of leukocytes as direct immune agents but also by the count of erythrocytes and platelets, which are not directly involved in the immune response. The number of particles of haplotype III of the BLV circulating in the blood of infected individuals exceeded that of the carriers of haplotype I. In this connection, an assumption was made about the evolutionary advantage of the more virulent haplotype III. However, the results of our own research in conjunction with the data of other scientists indicate that the high virulence of individual virus strains is a consequence of the tendency to implement the maximum possible intensity of the synthesis of virus particles but not of the high damaging effect alone. It is shown that high lethality is evolutionarily disadvantageous for viruses, since the extinction of the carrier as a biological species is fraught with the disappearance of the virus itself

The Mechanisms of Resistance to Tyrosine Kinase Inhibitor Imatinib Therapy of Chronic Myeloid Leukemia

Imatinib mesylate is a potent and high selective inhibitor of Bcr-Abl tyrosine kinase, which is established now as the standard of Philadelphia chromosome positive (Ph) chronic myeloid leukemia (CML) treatment. The treatment of patients with chronic phase of CML with imatinib has resulted in high rates of hematologic and cytogenetic responses. Nevertheless, primary and acquired resistance have been observed in few CML patients. The mechanisms of resistance to imatinib and its clinical significance were discussed in this review

Достоверность данных первичного зоотехнического учёта в молочном скотоводстве

The purpose of this paper is to evaluate the primary databases of zootechnical records in western Siberia. The object of the study was the records on milk productivity (milk yield during the whole lactation, milk fat content, milk protein content, amount of milk fat, amount of milk protein), duration of lactation (service period, dry period, inter-breeding period), age of the first fruitful insemination and information on the origin of 20,000 Holstein cows. The validity of the raw data was assessed by assuming a Gaussian distribution without significant human influence. For this purpose, the Anderson-Darling test and corresponding visualization using histograms and quantile-quantile plots were applied. The list of traits of milk production was based on the values of the Anderson-Darling criterion. The authors found that the highest levels of this criterion were correlated with milk fat and protein. And the indicator «milk yield» was practically absent from the list of traits of dairy productivity. These results can be explained by the fact that in most enterprises, the value of milk yield was higher than the appraisal threshold values. An analysis of the genealogical trees of the studied breeding enterprises was carried out, along with the use of statistical criteria. This analysis revealed the inappropriate assignment of several dozen of offspring to a single mother. Thus, the presented approach can be used to identify outliers associated with human factors. And it can also be related to improper methodological support of the sampling process and errors in the work of the laboratories of selective milk quality control associated with the sampling and delivery of samples.Целью настоящей работы является оценка баз данных первичного зоотехнического учёта в Западной Сибири. Объектом исследований были записи о молочной продуктивности (удой за всю лактацию, содержание жира в молоке, содержание белка в молоке, количество молочного жира, количество молочного белка), длительности лактации (сервис-период, сухостойный период, межотельный период), возраст первого плодотворного осеменения и сведения о происхождении 20000 коров голштинской породы. Оценку достоверности исходных данных осуществляли исходя из предположения о гауссовом распределении при отсутствии значимого влияния человеческого фактора. С этой целью применяли критерий Андерсона-Дарлинга и соответствующую визуализацию с использованием гистограмм и графиков квантиль–квантиль. Список признаков молочной продуктивности был составлен исходя из значений критерия Андерсона–Дарлинга. Установлено, что самые высокие уровни данного критерия соотносились с такими показателями, как молочный жир и белок, тогда как удой практически отсутствовал в перечне признаков молочной продуктивности. Это объясняется тем, что у животных большинства предприятий величина удоя была выше пороговых значений бонитировки. Наряду с использованием статистических критериев, проведен анализ генеалогических деревьев исследуемых племенных предприятий, который позволил выявить неправомерное отнесение нескольких десятков потомков к одной матери. Таким образом, представленный подход может быть использован для выявления выбросов, сопряженных с человеческим фактором, неправильным методическим обеспечением процесса отбора проб и ошибками в работе лабораторий селекционного контроля качества молока, связанными с отбором проб и их доставкой

What Is Stochastic Resonance? Definitions, Misconceptions, Debates, and Its Relevance to Biology

Stochastic resonance is said to be observed when increases in levels of unpredictable fluctuations—e.g., random noise—cause an increase in a metric of the quality of signal transmission or detection performance, rather than a decrease. This counterintuitive effect relies on system nonlinearities and on some parameter ranges being “suboptimal”. Stochastic resonance has been observed, quantified, and described in a plethora of physical and biological systems, including neurons. Being a topic of widespread multidisciplinary interest, the definition of stochastic resonance has evolved significantly over the last decade or so, leading to a number of debates, misunderstandings, and controversies. Perhaps the most important debate is whether the brain has evolved to utilize random noise in vivo, as part of the “neural code”. Surprisingly, this debate has been for the most part ignored by neuroscientists, despite much indirect evidence of a positive role for noise in the brain. We explore some of the reasons for this and argue why it would be more surprising if the brain did not exploit randomness provided by noise—via stochastic resonance or otherwise—than if it did. We also challenge neuroscientists and biologists, both computational and experimental, to embrace a very broad definition of stochastic resonance in terms of signal-processing “noise benefits”, and to devise experiments aimed at verifying that random variability can play a functional role in the brain, nervous system, or other areas of biology

Using mosaic crystals for the generation of intense X-ray beams

yesThe parametric X-ray (PXR) yield due to 500-MeV electrons in a 2-mm-thick diamond crystal with a mosaicity angle of ~0.2 mrad has been studied. It is shown that the mosaic crystal structure leads to a significant (about fourfold) increase in the PXR yield doe to the contribution of diffracted bremsstrahlung radiatio