185 research outputs found

    Digital-image analysis of the left common carotid artery in human foetuses

    Get PDF
    The rate of growth of the left common carotid artery during gestation has not been sufficiently evaluated. The present study was performed on 128 spontaneously aborted human foetuses aged 15&#8211;34 weeks to compile normative data for the dimensions of the left common carotid artery at varying gestational ages. Using anatomical dissection, digital image analysis (system of Leica Q Win Pro 16) and statistical analysis (ANOVA, regression analysis), a range of measurements (length, original external diameter and volume) for the left common carotid artery during gestation was examined. No significant gender differences were found (p > 0.05). The growth curves of the best fit for the plot of each morphometric parameter against gestational age were generated. The lengths ranged from 14.82 &#177; 2.22 to 42.84 &#177; 4.32 mm, according to the linear model y = -9.6918 + 1.5963 x &#177; 3.1706 (r = 0.95; p < 0.001). The original external diameter increased from 0.72 &#177; 0.18 to 3.28 &#177; 0.40 mm, according to the linear function y = &#8211;1.5228 + 0.1428 x &#177; 0.2749 (r = 0.95; p < 0.001). The left common carotid artery-to-aortic root diameter ratio increased from 0.356 &#177; 0.062 to 0.480 &#177; 0.101. The left common carotid artery-to-aortic arch diameter ratio increased from 0.447 &#177; 0.079 to 0.535 &#177; &#177; 0.113. The volume ranged from 6.73 &#177; 4.06 to 369.30 &#177; 107.42 mm3 in accordance with the quadratic function y = 344.8 &#8211; 41.001 x + 1.254 x2 &#177; &#177; 46.955 (R2 = 0.87). The parameters examined have clinical application in the early recognition of arterial abnormalities, especially aortic coarctation

    Digital expansions with negative real bases

    Full text link
    Similarly to Parry's characterization of β\beta-expansions of real numbers in real bases β>1\beta > 1, Ito and Sadahiro characterized digital expansions in negative bases, by the expansions of the endpoints of the fundamental interval. Parry also described the possible expansions of 1 in base β>1\beta > 1. In the same vein, we characterize the sequences that occur as (β)(-\beta)-expansion of ββ+1\frac{-\beta}{\beta+1} for some β>1\beta > 1. These sequences also describe the itineraries of 1 by linear mod one transformations with negative slope

    Machine learning method for data analysis millimeter astroclimate research

    Full text link
    В работе представлен метод оценки осаждаемого водяного пара по данным радиометра водяного пара с использованием методов машинного обучения. Проведен сравнительный анализ оценки осаждаемого водяного пара для обсерватории «Бадары» по данным GNSS, радиометра водяного пара и прогнозирования значений с использованием искусственной нейронной сети.The paper introduces a method for estimating precipitable water vapor using radiometer data with the help of machine learning techniques. A comparative analysis of the estimation of precipitable water vapor for the ”Badary” observatory has been conducted using GNSS data, radiometer data, and forecasted values through the utilization of an artificial neural network.Работа выполнена при поддержке гранта Российского научного фонда, проект № 23-22-00373

    Dense cores with signs of collapse in theMALT90 survey

    Full text link
    Представлена выборка из 33 источников обзора MALT90, имеющих спектры линий HCO+(1-0) с провалом и асимметрией, характерной для процессов сжатия плотных ядер и пригодных для изучения кинематики с помощью не-ЛТР моделирования переноса излучения. Двадцать ядер из N 2 012 было выбрано вручную на основе форм спектров линий HCO+(1-0), H13CO+(1-0), N^H+ (1-0) и карт интегральной интенсивности; 13 источников были выбраны с помощью статистического анализа, используя карты 0, 1 и 2 момента из 10 линий обзора, а также эллиптичности источника.A selection of 33 MALT90 survey sources is presented that have spectra of HCO+(1-0) lines with a self-absorbtion and blue asymmetry spectra indicate compression processes of dense cores and suitable for studying kinematics using non-LTE radiative transfer modeling. 20 cores from N 2 012 were manually selected based on the spectral profile of the lines HCO+(1-0), H13CO+(1-0), N^H+ (1-0) and integrated intensity maps. The 13 sources were selected through statistical analysis using moment 0, 1, and 2 maps from 10 sightlines as well as source ellipticity.Работа выполнена при поддержке гранта РНФ № 23-22-00139

    Transcriptional responses to glucose in Saccharomyces cerevisiae strains lacking a functional protein kinase A

    Get PDF
    Background The pattern of gene transcripts in the yeast Saccharomyces cerevisiae is strongly affected by the presence of glucose. An increased activity of protein kinase A (PKA), triggered by a rise in the intracellular concentration of cAMP, can account for many of the effects of glucose on transcription. In S. cerevisiae three genes, TPK1, TPK2, and TPK3, encode catalytic subunits of PKA. The lack of viability of tpk1 tpk2 tpk3 triple mutants may be suppressed by mutations such as yak1 or msn2/msn4. To investigate the requirement for PKA in glucose control of gene expression, we have compared the effects of glucose on global transcription in a wild-type strain and in two strains devoid of PKA activity, tpk1 tpk2 tpk3 yak1 and tpk1 tpk2 tpk3 msn2 msn4. Results We have identified different classes of genes that can be induced -or repressed- by glucose in the absence of PKA. Representative examples are genes required for glucose utilization and genes involved in the metabolism of other carbon sources, respectively. Among the genes responding to glucose in strains devoid of PKA some are also controlled by a redundant signalling pathway involving PKA activation, while others are not affected when PKA is activated through an increase in cAMP concentration. On the other hand, among genes that do not respond to glucose in the absence of PKA, some give a full response to increased cAMP levels, even in the absence of glucose, while others appear to require the cooperation of different signalling pathways. We show also that, for a number of genes controlled by glucose through a PKA-dependent pathway, the changes in mRNA levels are transient. We found that, in cells grown in gluconeogenic conditions, expression of a small number of genes, mainly connected with the response to stress, is reduced in the strains lacking PKA. Conclusions In S. cerevisiae, the transcriptional responses to glucose are triggered by a variety of pathways, alone or in combination, in which PKA is often involved. Redundant signalling pathways confer a greater robustness to the response to glucose, while cooperative pathways provide a greater flexibility.BT/BiotechnologyApplied Science

    Staphylococcus aureus Keratinocyte Invasion Is Dependent upon Multiple High-Affinity Fibronectin-Binding Repeats within FnBPA

    Get PDF
    Staphylococcus aureus is a commensal organism and a frequent cause of skin and soft tissue infections, which can progress to serious invasive disease. This bacterium uses its fibronectin binding proteins (FnBPs) to invade host cells and it has been hypothesised that this provides a protected niche from host antimicrobial defences, allows access to deeper tissues and provides a reservoir for persistent or recurring infections. FnBPs contain multiple tandem fibronectin-binding repeats (FnBRs) which bind fibronectin with varying affinity but it is unclear what selects for this configuration. Since both colonisation and skin infection are dependent upon the interaction of S. aureus with keratinocytes we hypothesised that this might select for FnBP function and thus composition of the FnBR region. Initial experiments revealed that S. aureus attachment to keratinocytes is rapid but does not require FnBRs. By contrast, invasion of keratinocytes was dependent upon the FnBR region and occurred via similar cellular processes to those described for endothelial cells. Despite this, keratinocyte invasion was relatively inefficient and appeared to include a lag phase, most likely due to very weak expression of α5β1 integrins. Molecular dissection of the role of the FnBR region revealed that efficient invasion of keratinocytes was dependent on the presence of at least three high-affinity (but not low-affinity) FnBRs. Over-expression of a single high-affinity or three low-affinity repeats promoted invasion but not to the same levels as S. aureus expressing an FnBPA variant containing three high-affinity repeats. In summary, invasion of keratinocytes by S. aureus requires multiple high-affinity FnBRs within FnBPA, and given the importance of the interaction between these cell types and S. aureus for both colonisation and infection, may have provided the selective pressure for the multiple binding repeats within FnBPA

    Virulence Characteristics and Genetic Affinities of Multiple Drug Resistant Uropathogenic Escherichia coli from a Semi Urban Locality in India

    Get PDF
    Extraintestinal pathogenic Escherichia coli (ExPEC) are of significant health concern. The emergence of drug resistant E. coli with high virulence potential is alarming. Lack of sufficient data on transmission dynamics, virulence spectrum and antimicrobial resistance of certain pathogens such as the uropathogenic E. coli (UPEC) from countries with high infection burden, such as India, hinders the infection control and management efforts. In this study, we extensively genotyped and phenotyped a collection of 150 UPEC obtained from patients belonging to a semi-urban, industrialized setting near Pune, India. The isolates representing different clinical categories were analyzed in comparison with 50 commensal E. coli isolates from India as well as 50 ExPEC strains from Germany. Virulent strains were identified based on hemolysis, haemagglutination, cell surface hydrophobicity, serum bactericidal activity as well as with the help of O serotyping. We generated antimicrobial resistance profiles for all the clinical isolates and carried out phylogenetic analysis based on repetitive extragenic palindromic (rep)-PCR. E. coli from urinary tract infection cases expressed higher percentages of type I (45%) and P fimbriae (40%) when compared to fecal isolates (25% and 8% respectively). Hemolytic group comprised of 60% of UPEC and only 2% of E. coli from feces. Additionally, we found that serum resistance and cell surface hydrophobicity were not significantly (p = 0.16/p = 0.51) associated with UPEC from clinical cases. Moreover, clinical isolates exhibited highest resistance against amoxicillin (67.3%) and least against nitrofurantoin (57.3%). We also observed that 31.3% of UPEC were extended-spectrum beta-lactamase (ESBL) producers belonging to serotype O25, of which four were also positive for O25b subgroup that is linked to B2-O25b-ST131-CTX-M-15 virulent/multiresistant type. Furthermore, isolates from India and Germany (as well as global sources) were found to be genetically distinct with no evidence to espouse expansion of E. coli from India to the west or vice-versa
    corecore