MyoD-positive myoblasts are present in mature fetal organs lacking skeletal muscle

The epiblast of the chick embryo gives rise to the ectoderm, mesoderm, and endoderm during gastrulation. Previous studies revealed that MyoD-positive cells were present throughout the epiblast, suggesting that skeletal muscle precursors would become incorporated into all three germ layers. The focus of the present study was to examine a variety of organs from the chicken fetus for the presence of myogenic cells. RT-PCR and in situ hybridizations demonstrated that MyoD-positive cells were present in the brain, lung, intestine, kidney, spleen, heart, and liver. When these organs were dissociated and placed in culture, a subpopulation of cells differentiated into skeletal muscle. The G8 antibody was used to label those cells that expressed MyoD in vivo and to follow their fate in vitro. Most, if not all, of the muscle that formed in culture arose from cells that expressed MyoD and G8 in vivo. Practically all of the G8-positive cells from the intestine differentiated after purification by FACS®. This population of ectopically located cells appears to be distinct from multipotential stem cells and myofibroblasts. They closely resemble quiescent, stably programmed skeletal myoblasts with the capacity to differentiate when placed in a permissive environment

A seasonal diary of phytoplankton in the North Atlantic

In recent years new biological and physical controls have been suggested to drive phytoplankton bloom dynamics in the North Atlantic. A better understanding of the mechanisms driving primary production has potentially important implications for the understanding of the biological carbon pump, as it has for prediction of the system in climate change scenarios. However, the scientific discussion regarding this topic has generally failed to integrate the different drivers into a coherent picture, often rendering the proposed mechanisms exclusive to each other. We feel that the suggested mechanisms are not mutually exclusive, but rather complementary. Thus, moving beyond the “single mechanism” point of view, here we present an integrated conceptual model of the physical and biological controls on phytoplankton dynamics in the North Atlantic. Further we believe that the acclimation of physiological rates can play an important role in mediating phytoplankton dynamics. Thus, this view emphasizes the occurrence of multiple controls and relates their variations in impact to climate change

Estimation of sinking velocities using free-falling dynamically scaled models: foraminifera as a test case

The velocity of settling particles is an important determinant of distribution in extinct and extant species with passive dispersal mechanisms, such as plants, corals, and phytoplankton. Here we adapt dynamic scaling, borrowed from engineering, to determine settling velocities. Dynamic scaling leverages physical models with relevant dimensionless numbers matched to achieve similar dynamics to the original object. Previous studies have used flumes, wind tunnels, or towed models to examine fluid flows around objects with known velocities. Our novel application uses free-falling models to determine the unknown sinking velocities of planktonic foraminifera – organisms important to our understanding of the Earth’s current and historic climate. Using enlarged 3D printed models of microscopic foraminifera tests, sunk in viscous mineral oil to match their Reynolds numbers and drag coefficients, we predict sinking velocities of real tests in seawater. This method can be applied to study other settling particles such as plankton, spores, or seeds

The role of diatom nanostructures in biasing diffusion to improve uptake in a patchy nutrient environment

Extent: 9 p.BACKGROUND: Diatoms are important single-celled autotrophs that dominate most lit aquatic environments and are distinguished by surficial frustules with intricate designs of unknown function. PRINCIPAL FINDINGS: We show that some frustule designs constrain diffusion to positively alter nutrient uptake. In nutrient gradients of 4 to 160 times over, 5 cm, the screened-chambered morphology of Coscincodiscus sp. biases the nutrient diffusion towards the cell by at least 3.8 times the diffusion to the seawater. In contrast, the open-chambers of Thalassiosira eccentrica produce at least a 1.3 times diffusion advantage to the membrane over Coscincodiscus sp. when nutrients are homogeneous. SIGNIFICANCE: Diffusion constraint explains the success of particular diatom species at given times and the overall success of diatoms. The results help answer the unresolved question of how adjacent microplankton compete. Furthermore, diffusion constraint by supramembrane nanostructures to alter molecular diffusion suggests that microbes compete via supramembrane topology, a competitive mechanism not considered by the standard smooth-surface equations used for nutrient uptake nor in microbial ecology and cell physiology.James G. Mitchell, Laurent Seuront, Mark J. Doubell, Dusan Losic, Nicolas H. Voelcker, Justin Seymour and Ratnesh La

Trait‐based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer

Plankton are an extremely diverse and polyphyletic group, exhibiting a large range in morphological and physiological traits. Here, we apply automated optical techniques, provided by the pulse‐shape recording automated flow cytometer—CytoSense—to investigate trait variability of phytoplankton and plastidic ciliates in Arctic and Atlantic waters of the subpolar North Atlantic. We used the bio‐optical descriptors derived from the CytoSense (light scattering [forward and sideward] and fluorescence [red, yellow/green and orange from chlorophyll a, degraded pigments, and phycobiliproteins, respectively]) and translated them into functional traits to demonstrate ecological trait variability along an environmental gradient. Cell size was the master trait varying in this study, with large photosynthetic microplankton (> 20 μm in cell diameter), including diatoms as single cells and chains, as well as plastidic ciliates found in Arctic waters, while small‐sized phytoplankton groups, such as the picoeukaryotes (< 4 μm) and the cyanobacteria Synechococcus were dominant in Atlantic waters. Morphological traits, such as chain/colony formation and structural complexity (i.e., cellular processes, setae, and internal vacuoles), appear to favor buoyancy in highly illuminated and stratified Arctic waters. In Atlantic waters, small cell size and spherical cell shape, in addition to photo‐physiological traits, such as high internal pigmentation, offer chromatic adaptation for survival in the low nutrient and dynamic mixing waters of the Atlantic Ocean. The use of automated techniques that quantify ecological traits holds exciting new opportunities to unravel linkages between the structure and function of plankton communities and marine ecosystems

Diagnostic system of the drive system of rail vehicles

W artykule omówiony został system diagnostyczny układu napędowego pojazdów szynowych ze szczególnym uwzględnieniem podatności diagnostycznej układu. Podano również wytyczne do opracowania modeli systemu diagnostycznego. Artykuł powstał w ramach projektów celowych: Prognozowanie stanu technicznego głównych systemów pojazdu szynowego na podstawie analizy zmian wartości charakterystycznych parametrów podzespołów (N N509 336637) i Mikroprocesorowy system diagnostyczny głównych systemów trakcyjnego pojazdu szynowego uwzględniający ocenę bieżącą i prognozowanie stanów (N RIO 0048 06/2009), finansowanych przez Ministerstwo Nauki i Szkolnictwa Wyższego.The diagnostic system of the drive system of railway vehicles with the special taking into consideration the diagnostic sensitivity of the system is discussed in this article. The guidelines to develop a diagnostic system of models are a/so given. This article was written as part of targeted projects: Forecasting the technical condition of the main systems of the rail vehicle on the basis of changes in the values of the characteristic parameters of subassemblies (N A/509 336637) and Microprocessor diagnostic system of the main systems of the railway traction vehicle taking into account the current assessment and prediction of conditions (N RIO 0048 06/2009) financed from the budget of the Ministry of Science and Higher Education

La population polonaise : doctrines, politique et conflits religieux

La population de la Pologne a fait l'objet de divers articles ou notes dans Population (1). La croissance démographique de ce pays a entraîné des difficultés économiques et suggéré des solutions qui s'écartent de la doctrine marxiste tout en aggravant le conflit entre l'Église catholique et l'État. L'avortement a été introduit également en d'autres pays socialistes, notamment en Hongrie et en Tchécoslovaquie, mais il ne semble pas que des raisons économiques aient, dans ces pays, été invoquées. L'accroissement de la population est du reste, beaucoup plus rapide en Pologne, en raison de la forte natalité. M. G. Miklasz, chargé de recherches à l'Institut d'économie et sociologie comparées, expose ici les données essentielles du problème.Miklasz Constant. La population polonaise : doctrines, politique et conflits religieux. In: Population, 15ᵉ année, n°2, 1960. pp. 317-332

Modernizacja wózków lokomotywy TEM 2 w celu zmniejszenia zanieczyszczenia eksploatacyjnego środowiska

The paper presents modernization of the TEM2 locomotive bogies with a view to adapt the present construction to higher requirements related to environmental protection. Modernization of the bogies is caused by modernization of the TEM2 locomotive itself. In consequence, a 19D locomotive is designed, that shall fulfill the requirements of relevant technical specifications for interoperability (TSI). Advisability of the bogie modernization is highlighted with consideration of environmental protection requirements. The goal was supported by the examples of other modernization tasks carried out to date in the Institute of Rail Vehicles “Tabor”. The design changes of the bogie subassemblies are presented, that are conducive directly to reduction of environmental pollution during the vehicle operation. The paper was prepared within the framework of the Applied Research Program 3 No PBS3/B6/33/2015 entitled “Series of modernized six-axis diesel locomotives meeting the requirements of European Union, making use of the locomotives in operation in Poland” implemented by the Institute of Rail Vehicles “Tabor” in Poznań and the Rail Vehicles “PESA” Bydgoszcz JSC.W artykule przedstawiono modernizację wózków lokomotywy TEM2 w zakresie dostosowania obecnej konstrukcji do zwiększonych wymagań ochrony środowiska. Modernizacja wózków jest związana z modernizacją lokomotywy TEM2 W wyniku modernizacji powstanie lokomotywa 19D spełniająca wymogi odpowiednich specyfikacji technicznych interoperacyjności (TSI). Opisano celowość modernizacji wózków w świetle wymagań ochrony środowiska. Cel został poparty przykładami z innych modernizacji wykonywanych do tej pory w Instytucie Pojazdów Szynowych „Tabor”. Przedstawiono zmiany konstrukcyjne w podzespołach wózka, które mają bezpośredni wpływ na zmniejszenie zanieczyszczenia środowiska podczas eksploatacji pojazdu. Artykuł powstał w ramach realizowanego projektu Programu Badań Stosowanych 3 nr Nr PBS3/B6/33/2015 pt. „Platforma zmodernizowanych spalinowych lokomotyw 6-osiowych spełniających wymagania Unii Europejskiej z wykorzystaniem lokomotyw eksploatowanych w kraju” wykonanego przez Instytut Pojazdów Szynowych „Tabor” w Poznaniu i Pojazdy Szynowe „PESA” Bydgoszcz S.A

Automated supervision systems for Limited Traffic Zones

More and more cities implement solution for motorized traffic reduction in separate areas of the cities. These areas include mostly cultural and historic centers, promenades and often all centers of large cities. To achieve traffic reduction, special fees for entrance to the city center are introduced and special bus lanes for emergency vehicles and public transport are isolated. Such solutions with paid or limited entrance to city centers occur in London and Berlin and dedicated bus lanes has also appeared in Poland in the major urban centers. These examples are often referred by the authorities of other cities wishing to introduce similar schemes. In order to effectively enforce the respect for the rules in Limited Traffic Zones automatic monitoring and supervision solutions are introduced. Automatic Number Plate Recognition (ANPR or ALPR – Automatic License Plate Recognition) is one of the elementary and most widely used system for LTZ security and effectiveness. ANPR allows the identification of the vehicles that appear on the entrances to the Limited Traffic Zone or move within the zone (for example, the bus lane). This article presents an implemented and successfully operating automatic Limited Traffic Zone in Katowice

Analysis of the antislip system building in with taking into account the potential constructional and operating errors

W artykule przedstawiono stosowane rozwiązania układów przeciwpoślizgowych instalowanych na wózkach pojazdów szynowych. Wyodrębniono i scharakteryzowano rozwiązania, które są obecnie stosowane. Określono miejsca powstawania potencjalnych błędów wykonawczych wpływających na zniekształcania sygnału generowanego w czujniku (nadajniku impulsów). Określono również miejsca powstawania błędów i ich wpływ na działanie układu przeciwpoślizgu w okresie eksploatacji. Podjęto próbę analizy wpływu w/w parametrów na jakość sygnału i na niezawodność działania układu wykonawczego (eliminację zjawiska poślizgu kół względem szyny). Przedstawiono algorytmy postępowania zmierzające, poprzez rozpoznanie miejsca powstawania błędu, do eliminacji zjawiska i maksymalnego wykorzystania możliwości jakie daje stosowany rodzaj układu przeciwpoślizgowego. Artykuł powstał w ramach projektu badawczo-rozwojowego Nr R 10 004806/2009pt. &quot;Mikroprocesorowy system diagnostyczny głównych systemów trakcyjnego pojazdu szynowego uwzględniający ocenę bieżącą i prognozowanie stanów &quot;, finansowanego z budżetu Ministerstwa Nauki i Szkolnictwa Wyższego.The used solutions of antislip systems installed on the bogies of rail vehicles are presented in this article. The solutions, which are being applied, are marked out and characterized. It is identified the places of occuring the potential performing errors affecting deformation of the signal that is generated in the sensor (pulse transmitter). It is also determined the places of occurring the errors and their impact on working of the antislip system during the operation. It i s also made an attempt to analyze the impact of the above mentioned parameters on the quality of signal and reliability of the executive system working (elimination of the phenomenon of wheel slip relative to the rail). It is presented the conducting algorithms aiming, by identifying the place of error occurring, to elimination of the phenomenon and to the maximum application of the possibilities offered by the used type of the antislip system. This article was elaborated within the research and development project No. R 10 004806/2009 entitled &quot;Microprocessor diagnostic system of the main systems of traction rail vehicle taking into account the current assessment and prediction of conditions&quot; fmanced from the budget of the Ministry of Science and Higher Education