Full-time dynamics of modulational instability in spinor Bose-Einstein condensates

We describe the full-time dynamics of modulational instability in F=1 spinor Bose-Einstein condensates for the case of the integrable three-component model associated with the matrix nonlinear Schroedinger equation. We obtain an exact homoclinic solution of this model by employing the dressing method which we generalize to the case of the higher-rank projectors. This homoclinic solution describes the development of modulational instability beyond the linear regime, and we show that the modulational instability demonstrates the reversal property when the growth of the modulation amplitude is changed by its exponential decay.Comment: 6 pages, 2 figures, text slightly extended, a reference adde

Partial monosomy 7q34-qter and 21pter-q22.13 due to cryptic unbalanced translocation t(7;21) but not monosomy of the whole chromosome 21: a case report plus review of the literature

<p>Abstract</p> <p>Background</p> <p>Autosomal monosomies in human are generally suggested to be incompatible with life; however, there is quite a number of cytogenetic reports describing full monosomy of one chromosome 21 in live born children. Here, we report a cytogenetically similar case associated with congenital malformation including mental retardation, motor development delay, craniofacial dysmorphism and skeletal abnormalities.</p> <p>Results</p> <p>Initially, a full monosomy of chromosome 21 was suspected as only 45 chromosomes were present. However, molecular cytogenetics revealed a de novo unbalanced translocation with a der(7)t(7;21). It turned out that the translocated part of chromosome 21 produced GTG-banding patterns similar to original ones of chromosome 7. The final karyotype was described as 45,XX,der(7)t(7;21)(q34;q22.13),-21. As a meta analysis revealed that clusters of the olfactory receptor gene family (ORF) are located in these breakpoint regions, an involvement of OFR in the rearrangement formation is discussed here.</p> <p>Conclusion</p> <p>The described clinical phenotype is comparable to previously described cases with ring chromosome 21, and a number of cases with del(7)(q34). Thus, at least a certain percentage, if not all full monosomy of chromosome 21 in live-borns are cases of unbalanced translocations involving chromosome 21.</p

QCD Instantons and the Soft Pomeron

We study the role of semi-classical QCD vacuum solutions in high energy scattering by considering the instanton contribution to hadronic cross sections. We propose a new type of instanton-induced interactions (``instanton ladder'') that leads to the rising with energy hadronic cross section of Regge type (the Pomeron). We argue that this interaction may be responsible for the structure of the soft Pomeron. The intercept is calculated. It has a non-analytic dependence on the strong coupling constant, allowing a non-singular continuation into the non-perturbative region. We derive the Pomeron trajectory, which appears to be approximately linear in some range of (negative) momentum transfer t, but exhibits a curvature at small t. Possible role of instantons in multiparticle production is also discussed.Comment: 20 pages, 8 figures, ReVTe

Instantons in the Saturation Environment

We show that instanton calculations in QCD become theoretically well defined in the gluon saturation environment which suppresses large size instantons. The effective cutoff scale is determined by the inverse of the saturation scale. We concentrate on two most important cases: the small-x tail of a gluon distribution of a high energy hadron or a large nucleus and the central rapidity region in a high energy hadronic or heavy ion collision. In the saturation regime the gluon density in a single large ultrarelativistic nucleus is high and gluonic fields are given by the classical solutions of the equations of motion. We show that these strong classical fields do not affect the density of instantons in the nuclear wave function compared to the instanton density in the vacuum. A classical solution with non-trivial topological charge is found for the gluon field of a single nucleus at the lowest order in the instanton perturbation theory. In the case of ultrarelativistic heavy ion collisions a strong classical gluonic field is produced in the central rapidity region. We demonstrate that this field introduces a suppression factor of exp{-c \rho^4 Q_s^4 / [8 \alpha^2 N_c (Q_s \tau)^2]} in the instanton size distribution, where Q_s is the saturation scale of both (identical) nuclei, \tau is the proper time and c = 1 is the gluon liberation coefficient. This factor suggests that gluonic saturation effects at the early stages of nuclear collisions regulate the instanton size distribution in the infrared region and make the instanton density finite by suppressing large size instantons.Comment: 20 pages, 8 figures, REVTeX, some discussion added including a possible scenario for unitarization of the soft pomero

Dynamical Supersymmetry Breaking

Supersymmetry is one of the most plausible and theoretically motivated frameworks for extending the Standard Model. However, any supersymmetry in Nature must be a broken symmetry. Dynamical supersymmetry breaking (DSB) is an attractive idea for incorporating supersymmetry into a successful description of Nature. The study of DSB has recently enjoyed dramatic progress, fueled by advances in our understanding of the dynamics of supersymmetric field theories. These advances have allowed for direct analysis of DSB in strongly coupled theories, and for the discovery of new DSB theories, some of which contradict early criteria for DSB. We review these criteria, emphasizing recently discovered exceptions. We also describe, through many examples, various techniques for directly establishing DSB by studying the infrared theory, including both older techniques in regions of weak coupling, and new techniques in regions of strong coupling. Finally, we present a list of representative DSB models, their main properties, and the relations between them.Comment: 113 pages, Revtex. Minor changes, references added and corrected. To appear in Reviews of Modern Physic

Efficacy of Endoscopic Submucosal Dissection for Superficial Gastric Neoplasia in a Large Cohort in North America

Background & Aims Endoscopic submucosal dissection (ESD) is a widely accepted treatment option for superficial gastric neoplasia in Asia, but there are few data on outcomes of gastric ESD from North America. We aimed to evaluate the safety and efficacy of gastric ESD in North America. Methods We analyzed data from 347 patients who underwent gastric ESD at 25 centers, from 2010 through 2019. We collected data on patient demographics, lesion characteristics, procedure details and related adverse events, treatment outcomes, local recurrence, and vital status at the last follow up. For the 277 patients with available follow-up data, the median interval between initial ESD and last clinical or endoscopic evaluation was 364 days. The primary endpoint was the rate of en bloc and R0 resection. Secondary outcomes included curative resection, rates of adverse events and recurrence, and gastric cancer-related death. Results Ninety patients (26%) had low-grade adenomas or dysplasia, 82 patients (24%) had high-grade dysplasia, 139 patients (40%) had early gastric cancer, and 36 patients (10%) had neuroendocrine tumors. Proportions of en bloc and R0 resection for all lesions were 92%/82%, for early gastric cancers were 94%/75%, for adenomas and low-grade dysplasia were 93%/ 92%, for high-grade dysplasia were 89%/ 87%, and for neuroendocrine tumors were 92%/75%. Intraprocedural perforation occurred in 6.6% of patients; 82% of these were treated successfully with endoscopic therapy. Delayed bleeding occurred in 2.6% of patients. No delayed perforation or procedure-related deaths were observed. There were local recurrences in 3.9% of cases; all occurred after non-curative ESD resection. Metachronous lesions were identified in 14 patients (6.9%). One of 277 patients with clinical follow up died of metachronous gastric cancer that occurred 2.5 years after the initial ESD. Conclusions ESD is a highly effective treatment for superficial gastric neoplasia and should be considered as a viable option for patients in North America. The risk of local recurrence is low and occurs exclusively after non-curative resection. Careful endoscopic surveillance is necessary to identify and treat metachronous lesions

Оптимизация параметров процесса резания швейных ниток

Процесите на рязане на нишки се използват широко в полуавтоматични машини за шивашката промишленост и представляват спешен проблем. Няма научно обоснована методология за проектиране на механизми за подрязване на нишки за полуавтоматични шевни машини.Рязането на нишки по метода на ножица не осигурява пълно рязане на всички компоненти на конеца в случай на недостатъчно притискане на равнините на ножа една към друга. За да се осигури цялостно подрязване, е разработена конструктивна схема за рязане и са получени формули за изчисление за определяне на силата, упражнена от нишката върху подвижния нож, като се вземат предвид механичните характеристики на нарязаната шевна нишка.Sewing thread cutting processes are widely used in semi-automatic machines of the garment industry, and is an urgent problem. There is no scientifically based methodology for designing thread trimming mechanisms for semi-automatic sewing machines. Cutting threads by the method of scissors does not provide complete cutting of all components of the thread in case of insufficient pressing of the knife planes to each other. To ensure complete trimming, a design cutting scheme has been developed and calculation formulas have been obtained for determining the force exerted by the thread on the movable knife, taking into account the mechanical characteristics of the cut sewing thread.Процессы нарезания швейной нити широко используются в полуавтоматических машинах швейной промышленности и являются актуальной проблемой. Не существует научно обоснованной методологии проектирования механизмов обрезки нитей для полуавтоматических швейных машин.Обрезка нитей ножничным методом не обеспечивает полной обрезки всех компонентов резьбы в случае недостаточного прижимания плоскостей ножа друг к другу. Для обеспечения полной обрезки была разработана расчетная схема обрезки и получены расчетные формулы для определения силы, прилагаемой нитью к подвижному ножу, с учетом механических характеристик обрезанной швейной нити

Expansion of Anopheles maculipennis s. s. (Diptera: Culicidae) to northeastern Europe and northwestern Asia: Causes and Consequences

BACKGROUND: The burden of malaria infection in the modern world remains significant. Specific changes in the relative proportions of malaria vector mosquitoes, Maculipennis Complex species, in the south of Western Siberia over the past 25 years of the 20(th) century have attracted wide attention as an indicator of their dynamic geographical distribution. In Eurasia, studies of fluctuations in the borders of areas occupied by sibling species of this complex, as well as their relative proportions in the areas where they are sympatric are epidemiologically important. METHODS: Species identity and chromosomal polymorphisms within each population were defined by cytogenetic analysis of polytene chromosomes of third- and fourth-instar larvae and adult females of Anopheles mosquitoes collected over the period from 1973 to 2012. A total of 37 Anopheles samples (3,757 specimens) from the Ukraine, European Russia and the Urals were studied. To identify An. messeae s.l. cryptic species A and B, polymerase chain reaction and restriction fragment length polymorphisms of the second internal transcribed spacer rRNA genes sequences (ITS2 PCR-RFLP) were used. RESULTS: An. maculipennis s.s. is expanding to the northeast at a speed of approximately 30 km per year. In 2008 or 2009, this species appeared in the Southern Urals. The emergence of An. maculipennis in this region was accompanied by a decrease in the proportions of An. messeae A and An. beklemishevi and by an increase in the proportion of An. messeae B within An. messeae s.l. It is highly likely that the southwestern border of An. beklemishevi distribution area could shift in the same direction as expanding area of An. maculipennis. CONCLUSIONS: The geographical distribution of the Palaearctic mosquito species of the Maculipennis Complex is undergoing a gradual shift. Changes detected in the species distribution can be considered as a component of the biocenotic process triggered by global warming. Both the warming itself and consequent expansion of An. maculipennis s.s. to the northeast, followed by changes in the species composition of Anopheles as well as their relative proportions and fluctuations in the species areas, exacerbate the epidemiology of malaria infection in Eurasia