Uniform expansivity outside the critical neighborhood in the quadratic family

We use rigorous numerical techniques to compute a lower bound for the exponent of expansivity outside a neighborhood of the critical point for thousands of intervals of parameter values in the quadratic family. We compute a possibly small radius of the critical neighborhood, and a lower bound for the corresponding expansivity exponent outside this neighborhood, valid for all the parameters in each of the intervals. We illustrate and study the distribution of the radii and these exponents. The results of our computations are mathematically rigorous. The source code of the software and the results of the computations are made publicly available at http://www.pawelpilarczyk.com/quadratic/..Comment: 12 pages, 7 figure

Inducing a map on homology from a correspondence

We study the homomorphism induced in homology by a closed correspondence between topological spaces, using projections from the graph of the correspondence to its domain and codomain. We provide assumptions under which the homomorphism induced by an outer approximation of a continuous map coincides with the homomorphism induced in homology by the map. In contrast to more classical results we do not require that the projection to the domain have acyclic preimages. Moreover, we show that it is possible to retrieve correct homological information from a correspondence even if some data is missing or perturbed. Finally, we describe an application to combinatorial maps that are either outer approximations of continuous maps or reconstructions of such maps from a finite set of data points

Topological-numerical analysis of a two-dimensional discrete neuron model

We conduct computer-assisted analysis of the two-dimensional model of a neuron introduced by Chialvo in 1995 (Chaos, Solitons & Fractals 5, 461-479). We apply the method for rigorous analysis of global dynamics based on a set-oriented topological approach, introduced by Arai et al. in 2009 (SIAM J. Appl. Dyn. Syst. 8, 757-789) and improved and expanded afterwards. Additionally, we introduce a new algorithm to analyze the return times inside a chain recurrent set. Based on this analysis, together with the information on the size of the chain recurrent set, we develop a new method that allows one to determine subsets of parameters for which chaotic dynamics may appear. This approach can be applied to a variety of dynamical systems, and we discuss some of its practical aspects. The data and the software described in the paper are available at http://www.pawelpilarczyk.com/neuron/

The dual role of Escherichia coli in the course of ulcerative colitis

BACKGROUND: This study examines the dual role of Escherichia coli in the course of ulcerative colitis (UC). The intestinal microbiota is considered to play an important role in UC pathogenesis, but how E. coli contributes to inflammation in UC is still unknown. On the one hand, we demonstrated that there was a significant increase in the number of E. coli at the sites of inflammation in patients with UC, which can lead to immune system activation, whilst, on the other hand, E. coli may contribute to the resolution of inflammatory reactions since E. coli can inhibit hydroxyl radical formation by eliminating substrates of the Fenton reaction, by assimilating ferrous iron (Fe(2+)) and inducing the decomposition of hydrogen peroxide (H(2)O(2)). On this way, E. coli may affect the initiation and/or prolongation of remission stages of UC. METHODS: Ten E. coli strains were isolated from the colonic mucosa of patients in the acute phase of UC. Using PCR, we examined the presence of genes encoding catalases (katG and katE) and proteins participating in iron acquisition (feoB, fepA, fhuA, fecA, iroN, fyuA, and iutA) in these E. coli strains. To determine if iron ions influence the growth rate of E. coli and its ability to decompose H(2)O(2), we grew E. coli in defined culture media without iron (M9(-)) or with ferrous ions (M9(Fe(2+))). Expression levels of genes encoding catalases were examined by real-time PCR. RESULTS: All investigated E. coli strains had catalase genes (katG, katE), genes coding for receptors for Fe(2+) (feoB) and at least one of the genes responsible for iron acquisition related to siderophores (fepA, fhuA, fecA, iroN, fyuA, iutA). E. coli cultured in M9(Fe(2+)) grew faster than E. coli in M9(-). The presence of Fe(2+) in the media contributed to the increased rate of H(2)O(2) decomposition by E. coli and induced katG gene expression. CONCLUSIONS: E. coli eliminates substrates of the Fenton reaction by assimilating Fe(2+) and biosynthesizing enzymes that catalyze H(2)O(2) decomposition. Thus, E. coli can inhibit hydroxyl radical formation, and affects the initiation and/or prolongation of remission stages of UC

Zakażenie HIV w praktyce lekarza podstawowej opieki zdrowotnej

Human immunodeficiency virus (HIV) infection is still a huge problem in medicine practice, both suspicious, diagnosis and treatment. Early recognition and good anti-retrovirus treatment caused elongation of life time, better quality of life, lower percent and lower risk opportunity infections, cancers connected with HIV infection and developing an acquired immune deficiency syndrome (AIDS). This article presents: risk factors of HIV infection and clinical syndromes connected with HIV.Zakażenie ludzkim wirusem niedoboru odporności (HIV) wciąż stanowi wśród lekarzy różnych specjalności duży problem, zarówno w kwestiach wysunięcia podejrzenia, postawienia diagnozy, jak i dalszego sprawowania opieki nad tą grupą pacjentów. Wczesne rozpoznanie i odpowiednio prowadzone leczenie antyretrowirusowe sprawiają, że znacznie wydłużył się czas przeżycia osób zakażonych, poprawiła się jakość ich życia, zmniejszył się odsetek i ryzyko wystąpienia zakażeń oportunistycznych, nowotworów związanych z zakażeniem oraz rozwinięcia się zespołu nabytego niedoboru odporności (AIDS). W pracy przedstawiono czynniki ryzyka zakażenia HIV oraz objawy kliniczne, mogące sugerować infekcję i wskazujące na konieczność wykonania testu przesiewowego w kierunku zakażenia HIV

Gorączka krwotoczna Ebola — realne zagrożenie?

Ebola hemorrhagic fever (EHF) is dangerous, high septic virus disease with very high level of mortality. Reservoir of this virus are some kinds of monkeys and fruitseaten bats. Infection is caused by direct contact with blood, organic fluids, excretions and discharges of sick person. Time of incubation is 21 days. Significant clinic symptoms are: high fever about 40 Celsius degrees , diarrhea, vomiting, and in the next stage: vomiting and diarrhea with blood, bleeding from nose, hemoptysis, hematuria, hemorrhagia from uterus. Suspicious of Ebola virus infection should be taken in every person after journey to tropical country , when 21 days later appears symptoms: fever, shivers, pain mussels, headache, soarthroat, diarrhea or vomiting. This person should be urgently send to reference clinics for diagnosis, observation and treatment.Gorączka krwotoczna Ebola (EHF) jest groźną, wysoce zakaźną chorobą wirusową, obarczoną wysoką śmiertelnością, której rezerwuarem są niektóre gatunki małp i owocożernych nietoperzy. Do zakażenia dochodzi drogą kontaktów bezpośrednich z krwią, płynami ustrojowymi, wydzielinami i wydalinami osoby chorej. Maksymalny okres wylęgania wynosi 21 dni. Do charakterystycznych objawów należą: wysoka gorączka do 40°C, biegunka, wymioty, a następnie dołączają się typowe objawy skazy krwotocznej — wymioty i biegunka z krwią, krwawienie z dziąseł, z nosa, krwioplucie, krwiomocz czy krwawienie z dróg rodnych. Podejrzenia zakażenia wirusem Ebola należy brać pod uwagę u każdej osoby, która powróciła z krajów tropikalnych i u której do 21 dni od powrotu pojawiły się objawy kliniczne: gorączka, dreszcze, bóle mięśni, stawów, ból głowy, gardła, biegunka czy wymioty. Takie osoby należy w trybie pilnym kierować do regionalnych ośrodków specjalistycznych — referencyjnych, celem diagnostyki, izolacji i dalszej obserwacji

Congenital cytomegaly — recommendations for diagnosis and therapy

Wrodzone zakażenie wirusem cytomegalii należy do najczęstszych zakażeń wewnątrz­macicznych. Wczesne rozpoznanie zakażenia CMV jest możliwe już w życiu płodowym lub bezpośrednio po narodzinach, co pozwala na rozpoczęcie odpowiedniego leczenia przyczy­nowego i zmniejszenie ryzyka powikłań. W rozpoznaniu stosuje się USG płodu, USG głowy noworodka, badania serologiczne przeciwciał anty-CMV i molekularne CMV-DNA z płynu owodniowego, moczu lub śliny. Do objawów klinicznych zakażenia należą opóźnienie rozwoju wewnątrzmacicznego, małogłowie, zwapnienia wewnątrzczaszkowe, żółtaczka, hepatosplenomegalia, osutka krwotoczna lub drobne wybroczyny na skórze, zapalenie siatkówki i naczyniówki, niedosłuch odbiorczy, zaburzenia rozwoju mowy i opóźnienie rozwoju psychoruchowego. W leczeniu stosuje się gancyklowir lub walgancyklowir. Z uwagi na narastający problem zakażeń CMV i zbyt późne rozpoznanie choroby, wskazane jest opracowanie badań przesiewowych i uświadomienie lekarzy ginekologów, neonatologów, pediatrów i lekarzy rodzinnych o istocie problemu. W pracy przedstawiono epidemiologię, rozpoznanie, przebieg i leczenie cytomegalii wrodzonej.Congenital cytomegaly is a most common intrauterus virus infect ion. Early diagnosis of CMV is possible during pregnancy or in very short time after deliver y and let us to star t treatment and lower a complications’ risk. To make a diagnosis is used a fetus ultrasound, CMV antybodies, CMV-DNA from amniotic fluid, urine or spittle. Clinical symptoms of in­fection caused: intrauterine growth retardation, microcephaly, intracranial calcifications, hepathosplenomegaly, jaundice, exanthema, retinitis, deafness, perturbation of speech development and psychomotor retardation. To treatment is used a gancyclovir and walgancyclovir. Still growing problem of CMV infections and to late diagnosis of it is suggestion for preparing screening tests and more education of gyneacologysts, neonatologysts, pediatrics and GP doctors about CMV problems. In this lecture we are presenting an epidemiology, diagnosis, process and treatment of congenital cytomegaly

Bacterial infections of the lower genital tract in fertile and infertile women from the southeastern Poland

Objectives: The objective of the study was to investigate the detection rates of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Gardnerella vaginalis, Escherichia coli, Streptococcus agalactiae and Enterococcus faecalis, showing no clinical signs of an ongoing, acute inflammatory state of the vagina and/or the cervix, in fertile and infertile women. Material and methods: The study encompassed 161 women, including 101 women treated for infertility and 60 fertile women who had already given birth to healthy children. The material for the presence of C. trachomatis, N. gonorrhoeae, M. genitalium, M. hominis and U. urealyticum was collected from the cervical canal and analyzed by PCR. Furthermore, BD ProbeTec ET system was used to detect C. trachomatis infection. Vaginal swabs were collected for classification of bacterial vaginosis and aerobic vaginitis and assessed according to the Nugent score, as well as by traditional culture methods. Results: U. urealyticum was identified in 9% of the infertile women and in 8% of controls. Presence of M. hominis was demonstrated only in the former (4%) and C. trachomatis only in latter (3%). N. gonorrhoeae and M. genitalium were not found in any of the examined women. The frequency of aerobic vaginitis in both groups was estimated at 12%. There were 7% bacterial vaginosis cases in the study group, and none in the control group (p=0.0096). Conclusions: Despite having no symptoms of an ongoing acute inflammation of the reproductive tract, many women may experience permanent or periodic shifts of equilibrium of the vaginal and/or cervical microflora. BV develops more frequently in infertile patients when compared to the fertile women