Genome Sequence of the Saprophyte Leptospira biflexa Provides Insights into the Evolution of Leptospira and the Pathogenesis of Leptospirosis

Leptospira biflexa is a free-living saprophytic spirochete present in aquatic environments. We determined the genome sequence of L. biflexa, making it the first saprophytic Leptospira to be sequenced. The L. biflexa genome has 3,590 protein-coding genes distributed across three circular replicons: the major 3,604 chromosome, a smaller 278-kb replicon that also carries essential genes, and a third 74-kb replicon. Comparative sequence analysis provides evidence that L. biflexa is an excellent model for the study of Leptospira evolution; we conclude that 2052 genes (61%) represent a progenitor genome that existed before divergence of pathogenic and saprophytic Leptospira species. Comparisons of the L. biflexa genome with two pathogenic Leptospira species reveal several major findings. Nearly one-third of the L. biflexa genes are absent in pathogenic Leptospira. We suggest that once incorporated into the L. biflexa genome, laterally transferred DNA undergoes minimal rearrangement due to physical restrictions imposed by high gene density and limited presence of transposable elements. In contrast, the genomes of pathogenic Leptospira species undergo frequent rearrangements, often involving recombination between insertion sequences. Identification of genes common to the two pathogenic species, L. borgpetersenii and L. interrogans, but absent in L. biflexa, is consistent with a role for these genes in pathogenesis. Differences in environmental sensing capacities of L. biflexa, L. borgpetersenii, and L. interrogans suggest a model which postulates that loss of signal transduction functions in L. borgpetersenii has impaired its survival outside a mammalian host, whereas L. interrogans has retained environmental sensory functions that facilitate disease transmission through water

Szybkość biegu młodych piłkarzy jest determinowana ich siłą i mocą

Introduction: For years researchers and trainers have been looking for determinants of sports talent in the youngest and also in the relationship between individual motor features relevant in given sport disciplines. There is a fundamental consensus in the opinion that the strength and power of the lower limbs are correlated with the speed of running. However, this relationship also among the youngest is not so clear. The purpose of the work was to show the relationship between strength and power generated during vertical jump and achieved height jump and the speed of flat running in the youngest footballers. Material and methods: The research covered 75 children training football at the age of 6-14 years divided into two age groups. The subjects made a countermovement jump on a dynamometric platform measuring strength, power, speed of rebound and the height obtained, after which they performed a flying run over a distance of 20m. Results: A strong, positive correlation was demonstrated between all dynamic and kinetic parameters of the jump and running speed. This correlation turned out to be clearly stronger in the older group of football players than in the younger group. Conclusions: The obtained results suggest that strength and power are good predictors, such an important feature in football as the player's motion speed, already at the basic level of training.Wprowadzenie: Od lat badacze i trenerzy szukają determinantów talentu sportowego u najmłodszych a także związku między poszczególnymi cechami motorycznymi, istotnymi w danych dyscyplinach sportowych. Istnieje fundamentalna zgoda w opinii, że siła i moc kończyn dolnych są skorelowane z prędkością biegu. Czy jednak korelacja ta występuje również u najmłodszych nie jest już tak jasne. Celem pracy jest wykazanie zależności pomiędzy siłą, mocą generowaną podczas wyskoku pionowego i osiągniętej wysokości a szybkością biegu płaskiego u najmłodszych piłkarzy nożnych. Materiał i metody: Badaniami objęto 75 dzieci trenujących piłkę nożną w wieku 6-14 lat, podzielonych na dwie grupy wiekowe. Badani wykonali skok dosiężny na platformie dynamometrycznej, z pomiarem siły, mocy, prędkości odbicia i uzyskanej wysokości, po czym wykonali bieg lotny na dystansie 20 m. Wyniki: Wykazano silną, dodatnią korelację między wszystkimi parametrami dynamicznymi i kinetycznymi skoku i prędkości biegu. Korelacja ta okazała się wyraźnie silniejsza w starszej grupie piłkarzy niż w młodszej grupie. Wnioski: Uzyskane wyniki sugerują, że siła i moc są dobrymi predyktorami ważnej w piłce nożnej cechy, jaką jest prędkość ruchu zawodnika, już na podstawowym poziomie treningu

Comparison of Various INDOT Testing Methods and Procedures to Quantify Variability in Measured Bituminous and Concrete Properties

This study was designed to analyze the variability associated with several test procedures used by the Indiana Department of Transportation (INDOT) in their Hot Mix Asphalt (HMA), portland cement concrete pavement (PCCP), and superstructure concrete protocols. The aim of this work was to document the variability associated with each of these test procedures toward application of this information of the development of acceptance criteria, pay factors, and pay incentives and disincentives. The studied parameters for HMA production included the air void content and VMA of the gyratory compacted mixture, in-place density, binder (asphalt) content, aggregate bulk specific gravity and water absorption, bulk specific gravity of compacted mixture, and theoretical maximum specific gravity. The analysis of existing INDOT test data and additional Purdue laboratory study indicated that testing variation was within or only slightly above the (1s) AASHTO limits for testing variation. The production variation ranged from 50 to 85% of the total variation depending on the tested parameter. The quality characteristics related to the acceptance program for PCC pavements and superstructure, which were investigated in this study, were plastic air content, flexural strength, and pavement thickness. Aggregate moisture and bulk specific gravity properties were also studied to determine what variations might be expected from a particular source. In addition to the QC/QA properties, compressive strength and split tensile strength of concrete were also studied. Based on the analysis of existing INDOT test data, it was found that all of the testing was within or only slightly above the (1s) AASHTO/ASTM testing variations. The production variation was found to range widely depending on the project. Overall, the study demonstrates that high quality testing is commonly performed in the state of Indiana and illustrates clear benefits of the technician certification programs and INDOT educational and training procedures

Fully Equipped Dynamic Model of a Bus

Nowadays, the time to market a new vehicle is crucial for every company as it is easier to meet the customers’ needs and expectations. However, designing a new vehicle is a long process which needs to take into account different performances. The most difficult is to predict a dynamic behavior of a vehicle especially when such a big vehicles as urban buses are considered. Therefore, there is a necessity to use a virtual model to investigate different performances. However, there is a lack of urban bus models that can fully reflect a dynamic behavior of the bus. This paper presents a fully equipped urban bus model which can be used to study a dynamic behavior of such vehicles. The model is based on innovative technique called cosimulation, which connects different modeling techniques (3D and 1D). Such a technique allows performing different analyses that require small deformations and large translations and rotations in shorter time and automatic way. The work has been carried out in a project EUREKA CHASING

Hybrydowe modelowanie autobusu miejskiego

Sophisticated virtual prototyping methods have become a standard in the modern vehicle design process. Unfortunately, in many cases automobile manufacturers (in particular bus manufacturers) still do not take advantage of numerical design techniques, basing instead on intuition and experience. In this paper hybrid modelling of an urban bus is presented. A hybrid bus model links different types of modelling that can be used to perform a wide range of virtual analyses of vehicle static and dynamic behaviour. The major objective of development and usage of a complex model is to reduce a time and cost of vehicle design process improving vehicle quality at the same time. The main advantage instead is a possibility to exploit a model for different performances of vehicle subsystems. A hybrid model representing real vehicle behaviour consists of three modelling techniques commonly used in automotive industry: multibody modelling, finite element modelling and multi- port (block) modelling. A full model has been developed via commercial software which ensures its availability among automotive engineers.Zaawansowane metody wirtualnego prototypowania są standardem w nowoczesnym procesie projektowania pojazdów. Niestety, w wielu przypadkach producenci pojazdów (a w szczególności autobusów) nadal nie odnoszą korzyści z numerycznych technik projektowania, opierając się raczej na intuicji i doświadczeniu. W niniejszym artykule zaprezentowano podejście hybrydowe w modelowaniu pojazdów samochodowych, opisane na przykładzie autobusu miejskiego. Model hybrydowy łączy różne typy modeli numerycznych, które są wykorzystane w szerokiej gamie wirtualnych analiz zachowania statycznego i dynamicznego pojazdów. Głównym celem opracowania i zastosowania kompleksowego modelu jest ograniczenie czasu i kosztów procesu projektowania pojazdów wraz z jednoczesną poprawą ich jakości. Główną zaletą natomiast jest możliwość wykorzystania modelu do analizy różnych podsystemów pojazdów. Model hybrydowy łączy techniki powszechnie stosowane w przemyśle motoryzacyjnym: modelowanie mechanizmów wieloczłonowych, modelowanie metodą elementów skończonych i modelowanie blokowe (wieloportowe), które w połączeniu tworzą w pełni wyposażony model odzwierciedlający rzeczywiste zachowanie pojazdu. Pełny model został opracowany z zastosowaniem komercyjnego oprogramowania, które zapewnia jego dostępność wśród inżynierów z branży motoryzacyjne

Model-based engineering-simulation based design of the suspension of city bus

Process of designing of vehicle suspension as a combination of springs and dampers is a very complicated task. In general it requires designing system respecting good ride comfort and good handling at the same time. It is obvious that these two aspects are dependent also of the type of the road on which vehicle is riding. Especially it is important in city buses which are workplaces for bus drivers and each day are transporting thousands of people. Bus suspension system is quite different from car suspension. Because of the mass and size instead of traditional springs, pneumatics springs are used. In some cases, values of damping and stiffness of the spring are adjusted to the proper road in a real bus while driving. It is necessary nowadays to have a virtual assessment that can simulate "bus suspension behaviour" to abstracted suspension parameters such as springs and dampers characteristics. In this paper a multibody model of city bus suspension has been presented. Multibody models are the best way of simulation of dynamic behaviour of the vehicle. Simulations showing how different types of the road affect the structure of the vehicle have been performed. Such prepared model can be then use as an input for optimization of the bus suspension in terms of ride comfort, handling, or even passengers' safety