Ploidy composition in all-hybrid frog populations in relation to ecological conditions

Question: What explains the differences in ratios of diploid (LR) and two types of triploid frogs (LLR, LRR) among all-hybrid frog populations? Hypothesis: Ecological conditions favouring one (LL) or the other (RR) parental species also favour those triploids that carry two copies of the respective genome (dosage effect), whereas diploids dominate under intermediate conditions. Organism: European water frog (Pelophylax esculentus). Field site: Thirty-four natural ponds in the province of Skåne, southern Sweden. Methods: We caught more than 3000 frogs, determined their genotypes with microsatellites, and related the ploidy composition to several uncorrelated ecological parameters, including pond morphology, vegetation, and physical and chemical water parameters. Conclusions: We found a shift from predominantly LLR in small isolated ponds to more LRR in large wetland ponds. This parallels the preferences of the parental species LL and RR for small and large bodies of water, respectively. The effects that pond vegetation and physico-chemical water parameters exert on the parental species were not found in all-hybrid populations. This suggests that environmental parameters affect the genotype composition of all-hybrid populations less than populations containing the parental species. Pond-to-pond differences in LR, LLR, and LRR proportions seem to be better explained by differences in gamete production and thus inheritance patterns

Organisation der Notfallstation: Umfeld und Leistungsauftrag bestimmen das Organisationskonzept

Zusammenfassung: Untersuchungsziel: Organisationsformen von Notfallstationen wurden analysiert, um Gestaltungsgrundsätze abzuleiten. Methoden: Organisation und Leistungsauftrag der klinischen Notfallmedizin wurden anhand einer Literaturrecherche verglichen. Dabei wurden organisatorische Grundmuster in Abhängigkeit von der Anwesenheit von Spezialisten (Spezialisierung) und der Einbindung in die Spitalorganisation (Integration) entwickelt und aufgrund etablierter Effizienzkriterien vergleichend bewertet. Ergebnisse: Klinische Notfallstationen unterscheiden sich hinsichtlich Autonomiegrad, Leistungsbreite und Leistungstiefe. Vier Archetypen wurden abgegrenzt: Das Profit-Center als ertragsorientierte Wirtschaftseinheit, das Service-Center als auftragserfüllende Organisationseinheit, die funktionelle Organisation als fachlich abgegrenzte Einheit und die modulare Organisation, die sich durch eine zentrale Notfalleinheit und rasch mobilisierbare Spezialistenteams auszeichnet. Schlussfolgerungen: Es gibt keinen Königsweg. Jede organisatorische Lösung bietet in Abhängigkeit von Umfeldbedingungen und Leistungsauftrag Vor- und Nachteile. Die organisatorischen Grundmuster bieten eine Orientierungshilfe, wobei Leistungsvolumen und -spektrum wichtige Determinanten darstelle

Engineering human cell-based, functionally integrated osteochondral grafts by biological bonding of engineered cartilage tissues to bony scaffolds

In this study, we aimed at developing and validating a technique for the engineering of osteochondral grafts based on the biological bonding of a chondral layer with a bony scaffold by cell-laid extracellular matrix. Osteochondral composites were generated by combining collagen-based matrices (Chondro-Gide) containing human chondrocytes with devitalized spongiosa cylinders (Tutobone) using a fibrin gel (Tisseel). We demonstrate that separate pre-culture of the chondral layer for 3 days prior to the generation of the composite allows for (i) more efficient cartilaginous matrix accumulation than no pre-culture, as assessed histologically and biochemically, and (ii) superior biological bonding to the bony scaffold than 14 days of pre-culture, as assessed using a peel-off mechanical test, developed to measure integration of bilayered materials. The presence of the bony scaffold induced an upregulation in the infiltrated cells of the osteoblast-related gene bone sialoprotein, indicative of the establishment of a gradient of cell phenotypes, but did not affect per se the quality of the cartilaginous matrix in the chondral layer. The described strategy to generate osteochondral plugs is simple to be implemented and--since it is based on clinically compliant cells and materials--is amenable to be readily tested in the clinic

Self-Rated Health as a Predictor of Death after Two Years:The Importance of Physical and Mental Wellbeing Postintensive Care

Introduction. The objective of this study is, among half-year intensive care survivors, to determine whether self-assessment of health can predict two-year mortality. Methods. The study is a prospective cohort study based on the Procalcitonin and Survival Study trial. Half-year survivors from this 1200-patient multicenter intensive care trial were sent the SF-36 questionnaire. We used both a simple one-item question and multiple questions summarized as a Physical Component Summary (PCS) and a Mental Component Summary (MCS) score. The responders were followed for vital status 730 days after inclusion. Answers were dichotomized into a low-risk and a high-risk group and hazard ratios (HR) with 95% confidence interval (CI) were calculated by Cox proportional hazard analyses. Conclusion. We found that self-rated health measured by a single question was a strong independent predictor of two-year all-cause mortality (HR: 1.8; 95% CI: 1.1–3.0). The multi-item component scores of the SF-36 also predicted two-year mortality (PCS: HR: 2.9; 95% CI 1.7–5.0) (MCS: HR: 1.9; 95% CI 1.1–3.4). These results suggest that self-rated health questions could help in identifying patients at excess risk. Randomized controlled trials are needed to test whether our findings represent causality

Antenna-coupled spintronic terahertz emitters driven by a 1550 nm femtosecond laser oscillator

We demonstrate antenna-coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna-coupled devices to those without antennas. Using a 200 μm H-dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42-fold larger THz peak-peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 μm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a commercial fiber-coupled system that is frequently employed in table-top THz time-domain systems. This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through Project Nos. 290319996/TRR173, 318612841, and 278381540/PR1413/3-1 (REPHCON) and project B02 of the SFB/TRR227 Ultrafast Spin Dynamics. We further acknowledge CST for the EM Simulation solver

Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13280-016-0867-5) contains supplementary material, which is available to authorized users

Subamorphous thermal conductivity of crystalline half-Heusler superlattices

En publicar-se l'article, l'autor Emigdio Chávez treballa a l'Institut Català de Nanociència i NanotecnologiaThe quest to improve the thermoelectric figure of merit has mainly followed the roadmap of lowering the thermal conductivity while keeping unaltered the power factor of the material. Ideally an electron-crystal phonon-glass system is desired. In this work, we report an extraordinary reduction of the cross-plane thermal conductivity in crystalline (TiNiSn):(HfNiSn) half-Heusler superlattices (SLs). We create SLs with thermal conductivities below the effective amorphous limit, which is kept in a large temperature range (120-300 K). We measured thermal conductivity at room temperature values as low as 0.75 W m⁻¹ K⁻¹, the lowest thermal conductivity value reported so far for half-Heusler compounds. By changing the deposition conditions, we also demonstrate that the thermal conductivity is highly impacted by the way the single segments of the SL grow. These findings show a huge potential for thermoelectric generators where an extraordinary reduction of the thermal conductivity is required but without losing the crystal quality of the syste