Spontaneous hybridisation of wild and cultivated species in Argentina

Un proyecto checo-argentino sobre la investigación de poblaciones de recursos genéticos - parientes silvestres de cultivos, cultivos asilvestrados e híbridos espontáneos con especies cultivadas - en el territorio de ambos países, fue propuesto con el objetivo de recopilar información sobre su distribución y para recoger muestras de semillas para futuras investigaciones. Fueron encontradas plantas híbridas de girasol y sorgo en 11 localidades y se recolectaron muestras de herbario y semillas. Las localidades fueron caracterizadas ecológicamente y desde el punto de vista de su vegetación y se evaluaron los factores de amenaza como requisito previo para la planificación de conservación in situ. En total, 52 localidades fueron visitadas y se recolectaron 36 muestras, incluyendo parientes silvestres.Czech-Argentinean project on genetic resources population investigation – crop wild relatives, escapes from cultivation and spontaneous hybrids with cultivated species – on the territory of both countries, was proposed with an aim to gather information on their distribution and to collect seed samples for further research. Hybrid plants of sunflower and sorghum were found on 11 localities. Herbarium and seeds samples were collected. Found localities were characterised ecologically and from the point of view of vegetation, and threat factors were assessed as prerequisite for in situ conservation planning. The total number of visited sites was 52 and collected samples 36 including crop wild relatives.Česko-Argentinský projekt na výzkum populací genetických zdrojů - planých příbuzných druhů, zplanělých druhů a hybridů s kulturními druhy byl navržen s cílem shromáždit informace o rozšíření spontánních hybridů a sebrat semenné vzorky. Hybridní rostliny slunečnice a čiroku byly nalezeny na 11 lokalitách. Byly odebrány herbářové doklady a sebrána semena. Nalezené lokality byly charakterizovány ekologicky i vegetačně a byly posouzeny faktory ohrožení nezbytné pro plánování in situ konzervace. Celkem bylo navštíveno 52 lokalit s planými příbuznými druhy a sebráno 36 semenných vzorků.Fil: Holubec, Voytech. Výzkumný ústav rostlinné výroby. v.v.i.; EsloveniaFil: Vymyslický T.. Zemědělský výzkum. spol. s r. o; República ChecaFil: Poverene, Maria Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Cantamutto, M.. Universidad Nacional del Sur. Departamento de Agronomía; Argentin

Compression coil provides increased lead control in extraction procedures

Aims We investigated a new lead extraction tool (Compression Coil; One-Tie, Cook Medical) in an experimental traction force study. Methods and results On 13 pacemaker leads (Setrox JS53, Biotronik) traction force testing was performed under different configurations. The leads were assigned to three groups: (i) traction force testing without central locking stylet support (n = 5), (ii) traction force testing with the use of a locking stylet (Liberator, Cook Medical) and a proximal ligation suture (n = 4), (iii) traction force testing with the use of a locking stylet and a compression coil (n = 4). The following parameters were obtained for all groups: stress-strain curves, maximal forces, elastic modulus, post-testing lead length and lead elongation. In Groups 2 and 3 retraction of the locking stylet within the lead was measured [lead tip-locking stylet distance (LTLSD)]. Maximal forces for the three groups were: (i) 28.3 ± 0.3 N; (ii) 30.6 ± 3.0 N; (iii) 31.6 ± 2.9 N (1 vs. 2, P = 0.13; 1 vs. 3, P = 0.04; 2 vs. 3, P = 0.65). Elastic modulus was (i) 22.8 ± 0.1 MPa; (ii) 2830.8 ± 351.1 MPa; (iii) 2447.0 ± 510.5 MPa (1 vs. 2, P < 0.01; 1 vs. 3, P < 0.01; 2 vs. 3, P = 0.26). Mean LTLSD in Group 2 was 19.8 ± 3.2 cm and was 13.8 ± 1.7 cm in Group 3 (P = 0.02). The ratio of LTLSD/post-testing lead length was 0.37 ± 0.03 for Group 2 and 0.24 ± 0.03 for Group 3 (P < 0.01). Conclusion The application of a compression coil leads to an increased lead control expressed by less retraction of the locking stylet within the lead. This enables improved central support of extraction sheaths in the case of challenging extraction procedure

Antigenic Protein In Microgravity-Grown Human Mixed Mullerian Tumor (LN1) Cells Preserved In RNA Stabilizing Agent

Cells treated with RNAlater(TradeMark) have previously been shown to contain antigenic proteins that can be visualized using Western blot analysis. These proteins seem to be stable for several months when stored in RNA stabilizer at 4 C. Antigenic protein can be recovered from cells that have been processed using an Ambion RNAqueous(Registered TradeMark) kit to remove RNA. In this set of experiments, human mixed Mullerian tumor (LN1) cells grown on the International Space Station during Expedition 3 were examined for antigenic stability after removal of RNA. The cells were stored for three months in RNAlater(TradeMark) and RNA was extracted. The RNA filtrate Containing the protein was precipitated, washed, and suspended in buffer containing sodium dodecyl sulfate (SDS). Samples containing equal concentrations of protein were loaded onto SDS-polyacrylamide gels. Proteins were separated by electrophoresis and transferred by Western blot to polyvinylidene fluoride (PVDF) membrane. The Western blots were stained with an enhanced chemiluminescent ECL(Registered TradeMark)Plus detection kit (Amersham) and scanned using a Storm 840 gel image analyzer (Amersham, Molecular Dynamics). ImageQuant(Registered TradeMark)a software was used to quantify the densities of the protein bands. The ground control and flight LN1 cell samples showed a similar staining pattern over time with antibodies to vimentin, glyceraldehyde-3-phosphate dehydrogenase, and epithelial membrane antigens

Quality of life after aortic valve repair is similar to Ross patients and superior to mechanical valve replacement: A cross-sectional study

Background: In patients after aortic valve surgery, the quality of life is hypothesized to be influenced by the type of the valve procedure. A cross-sectional study on the postoperative quality of life was carried out in patients after aortic valve-sparing surgery (with regards to the age of the patient), Ross procedure and mechanical aortic valve replacement. Methods: Quality of life was studied in 139 patients after aortic valve surgery divided into four study groups (Y - aortic valve-sparing procedure at the age below 50years, mean age 36.2years; O - aortic valve-sparing procedure at the age 50years and over, mean age 59.2years; R - Ross procedure, mean age 37.8years and M - mechanical aortic valve replacement at the age below 50years, mean age 39.2years). SF-36 Short Form and valve-specific questionnaires were mailed to the patients after 6months or later following surgery (median 26.9months). Results: In SF-36, the younger aortic valve repair patients and the Ross patients scored significantly better in 4 of 4 physical subscales and in 2 of 4 mental subscales than the older aortic valve repair and mechanical valve replacement patients. In the valve-specific questionnaire; however, all 3 groups free of anticoagulation (Y, O, and R) displayed greater freedom from negative valve-related concerns. Conclusions: Postoperative quality of life is influenced by the type of aortic valve procedure and is negatively linked with mechanical prosthesis implantation and long-term anticoagulation. Aortic valve-sparing strategy should be considered in cases with suitable valve morphology due to favorable clinical results and beneficial impact on the long-term quality of life

Proteomic Retrieval from Nucleic Acid Depleted Space-Flown Human Cells

Compared to experiments utilizing humans in microgravity, cell-based approaches to questions about subsystems of the human system afford multiple advantages, such as crew safety and the ability to achieve statistical significance. To maximize the science return from flight samples, an optimized method was developed to recover protein from samples depleted of nucleic acid. This technique allows multiple analyses on a single cellular sample and when applied to future cellular investigations could accelerate solutions to significant biomedical barriers to human space exploration. Cell cultures grown in American Fluoroseal bags were treated with an RNA stabilizing agent (RNAlater - Ambion), which enabled both RNA and immunoreactive protein analyses. RNA was purified using an RNAqueous(registered TradeMark) kit (Ambion) and the remaining RNA free supernatant was precipitated with 5% trichloroacetic acid. The precipitate was dissolved in SDS running buffer and tested for protein content using a bicinchoninic acid assay (1) (Sigma). Equal loads of protein were placed on SDS-PAGE gels and either stained with CyproOrange (Amersham) or transferred using Western Blotting techniques (2,3,4). Protein recovered from RNAlater-treated cells and stained with protein stain, was measured using Imagequant volume measurements for rectangles of equal size. BSA treated in this way gave quantitative data over the protein range used (Fig 1). Human renal cortical epithelial (HRCE) cells (5,6,7) grown onboard the International Space Station (ISS) during Increment 3 and in ground control cultures exhibited similar immunoreactivity profiles for antibodies to the Vitamin D receptor (VDR) (Fig 2), the beta isoform of protein kinase C (PKC ) (Fig 3), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (Fig 4). Parallel immunohistochemical studies on formalin-fixed flight and ground control cultures also showed positive immunostaining for VDR and other biomarkers (Fig 5). These results are consistent with data from additional antigenic recovery experiments performed on human Mullerian tumor cells cultured in microgravity (8)

A minimal model of an autonomous thermal motor

We consider a model of a Brownian motor composed of two coupled overdamped degrees of freedom moving in periodic potentials and driven by two heat reservoirs. This model exhibits a spontaneous breaking of symmetry and gives rise to directed transport in the case of a non- vanishing interparticle interaction strength. For strong coupling between the particles we derive an expression for the propagation velocity valid for arbitrary periodic potentials. In the limit of strong coupling the model is equivalent to the B\"uttiker-Landauer model [1-3] for a single particle diffusing in an environment with position dependent temperature. By using numerical calculations of the Fokker-Planck equation and simulations of the Langevin equations we study the model for arbitrary coupling, retrieving many features of the strong coupling limit. In particular, directed transport emerges even for symmetric potentials. For distinct heat reservoirs the heat currents are well-defined quantities allowing a study of the motor efficiency. We show that the optimal working regime occurs for moderate coupling. Finally, we introduce a model with discrete phase space which captures the essential features of the continuous model, can be solved in the limit of weak coupling, and exhibits a larger efficiency than the continuous counterpart.Comment: Revised version. Extended discussion on the discrete model. To appear in EP

Energetics and performance of a microscopic heat engine based on exact calculations of work and heat distributions

We investigate a microscopic motor based on an externally controlled two-level system. One cycle of the motor operation consists of two strokes. Within each stroke, the two-level system is in contact with a given thermal bath and its energy levels are driven with a constant rate. The time evolution of the occupation probabilities of the two states are controlled by one rate equation and represent the system's response with respect to the external driving. We give the exact solution of the rate equation for the limit cycle and discuss the emerging thermodynamics: the work done on the environment, the heat exchanged with the baths, the entropy production, the motor's efficiency, and the power output. Furthermore we introduce an augmented stochastic process which reflects, at a given time, both the occupation probabilities for the two states and the time spent in the individual states during the previous evolution. The exact calculation of the evolution operator for the augmented process allows us to discuss in detail the probability density for the performed work during the limit cycle. In the strongly irreversible regime, the density exhibits important qualitative differences with respect to the more common Gaussian shape in the regime of weak irreversibility.Comment: 21 pages, 7 figure

Conformal mappings versus other power series methods for solving ordinary differential equations: illustration on anharmonic oscillators

The simplicity and the efficiency of a quasi-analytical method for solving nonlinear ordinary differential equations (ODE), is illustrated on the study of anharmonic oscillators (AO) with a potential $V(x) =\beta x^{2}+x^{2m}$ ($m>0$). The method [Nucl. Phys. B801, 296 (2008)], applies a priori to any ODE with two-point boundaries (one being located at infinity), the solution of which has singularities in the complex plane of the independent variable $x$. A conformal mapping of a suitably chosen angular sector of the complex plane of $x$ upon the unit disc centered at the origin makes convergent the transformed Taylor series of the generic solution so that the boundary condition at infinity can be easily imposed. In principle, this constraint, when applied on the logarithmic-derivative of the wave function, determines the eigenvalues to an arbitrary level of accuracy. In practice, for $\beta \geq 0$ or slightly negative, the accuracy of the results obtained is astonishingly large with regards to the modest computing power used. It is explained why the efficiency of the method decreases as $\beta$ is more and more negative. Various aspects of the method and comparisons with some seemingly similar methods, based also on expressing the solution as a Taylor series, are shortly reviewed, presented and discussed.Comment: 32 pages, 7 figures, 8 table