Un podologo bovino racconta

Roman Zimmermann, contadino, podologo bovino e docente presso lo Schluechthof sa come mantenere sani gli unghioni e che fare in presenza di Mortellaro

Musterbildung im Maisembryo: Klonierung NAM/CUC-Orthologer aus Zea mays L.

Zusammenfassung Im Vergleich zu Arabidopsis ist der Kenntnisstand über die Musterbildung im Maisembryo rudimentär und beruht hauptsächlich auf histologischen Studien. Essentiell für die postembryonale Entwicklung ist die Anlage der beiden apikalen Meristeme im Embryo. Im Gegensatz zu Arabidopsis wird in Zea mays das sprossapikale Meristem (SAM) nicht an apiko-zentraler, sondern an lateraler Position auf der adaxialen, dem Skutellum gegenüber-liegenden Seite des Embryos angelegt. In dikotylen Spezies konnten Mitglieder der konservierten NAC Genfamilie wie NO APICAL MERISTEM aus Petunia (PhNAM) oder die CUP-SHAPED COTYLEDON Gene aus Arabidopsis (AtCUC1-3) als essentiell für die Initiation des SAM und Organseparation identifiziert werden. Im Rahmen der vorliegenden Arbeit wurde die Etablierung putativer PhNAM/AtCUC-Orthologer als molekulare Marker für die Visualisierung von Musterbildungsprozessen, die der SAM-Initiation in Mais zugrunde liegen, angestrebt. Basierend auf Sequenzhomologien wurden 6 NAC Gene isoliert und phylogenetisch klassifiziert. Darüber hinaus wurden korrespondierende Kartierungspositionen im Maisgenom bestimmt. ZmCUC3 und die potentiellen Paraloge ZmNAM1/2 zeigen höchste Homologie zu AtCUC3 bzw. PhNAM, welche in Monokotylen wie Dikotylen diskrete, evolutiv konservierte Genfunktionen darstellen. Dabei werden ZmNAM1/2 wie AtCUC1/2 vermutlich über miRNAs reguliert. Die hohe Sequenzverwandtschaft deutet in Kombination mit den auffälligen Gemeinsamkeiten in den Expressionsmustern darauf hin, dass ZmNAM1/2 und ZmCUC3 wie ihre nächsten dikotylen Verwandten zu SAM Initiation und Organseparation in Zea mays beitragen. ZmNAC4 und die potentiellen Paraloge ZmNAC5/6 werden in phylogenetischen Rekonstruktionen bisher weitestgehend unbekannten Vertretern zugeordnet. ZmNAC4 stellt einen frühen und selektiven Marker für die Spezifizierung von Endosperm-Zellschicksal dar. ZmNAC5/6 sind eng mit der Entstehung der Koleorrhiza bzw. Wurzelhaube assoziiert. Durch die Analyse des ZmSCR-Transkriptionsmusters in räumlicher und zeitlicher Relation zu dem von Kn1 bzw. ZmNAC5/6 ergeben sich weiterhin folgende Erkenntnisse über die Musterbildung im Maisembryo: 1. Zellen des Wurzelmeristems werden räumlich und zeitlich diskret von denen des SAM spezifiziert. 2. Die Kalyptra wird bereits embryonal als Teil der Koleorrhiza angelegt. 3. Die Spross-Wurzelachse wird im Embryo als diskrete Subgruppe von Zellen des basalen Suspensors bzw. Skutellums abgegrenzt - Kn1 kommt dabei eine zentrale Stellung zu. 4. Der Gewebespalt zwischen lateralen Bereichen von Wurzel und Koleorrhiza wird über lokale Zellwandauflösung errichtet

Intra-annual radial growth and water relations of trees: implications towards a growth mechanism

There is a missing link between tree physiological and wood-anatomical knowledge which makes it impossible mechanistically to explain and predict the radial growth of individual trees from climate data. Empirical data of microclimatic factors, intra-annual growth rates, and tree-specific ratios between actual and potential transpiration (T PET−1) of trees of three species (Quercus pubescens, Pinus sylvestris, and Picea abies) at two dry sites in the central Wallis, Switzerland, were recorded from 2002 to 2004 at a 10 min resolution. This included the exceptionally hot and dry summer of 2003. These data were analysed in terms of direct (current conditions) and indirect impacts (predispositions of the past year) on growth. Rain was found to be the only factor which, to a large extent, consistently explained the radial increment for all three tree species at both sites and in the short term as well. Other factors had some explanatory power on the seasonal time-scale only. Quercus pubescens built up much of its tree ring before bud break. Pinus sylvestris and Picea abies started radial growth 1-2 weeks after Quercus pubescens and this was despite the fact that they had a high T PET−1 before budburst and radial growth started. A high T PET−1 was assumed to be related to open stomata, a very high net CO2 assimilation rate, and thus a potential carbon (C)-income for the tree. The main period of radial growth covered about 30-70% of the productive days of a year. In terms of C-allocation, these results mean that Quercus pubescens depended entirely on internal C-stores in the early phase of radial growth and that for all three species there was a long time period of C-assimilation which was not used for radial growth in above-ground wood. The results further suggest a strong dependence of radial growth on the current tree water relations and only secondarily on the C-balance. A concept is discussed which links radial growth over a feedback loop to actual tree water-relations and long-term affected C-storage to microclimat

Configuring Poetic Time: Figures of Movement and Perception in Marcel Proust’s À la recherche du temps perdu

Gibhardt BR. Configuring Poetic Time: Figures of Movement and Perception in Marcel Proust’s À la recherche du temps perdu. In: Zimmermann MF, ed. Vision in motion: streams of sensation and configurations time. Zürich: diaphnes; 2016: 361-374

Deep Learning-Assisted Nephrotoxicity Testing with Bioprinted Renal Spheroids

We used arrays of bioprinted renal epithelial cell spheroids for toxicity testing with cisplatin. The concentration-dependent cell death rate was determined using a lactate dehydrogenase assay. Bioprinted spheroids showed enhanced sensitivity to the treatment in comparison to monolayers of the same cell type. The measured dose-response curves revealed an inhibitory concentration of the spheroids of IC $_{50}$ = 9 ± 3 μM in contrast to the monolayers with IC $_{50}$ = 17 ± 2 μM. Fluorescent labeling of a nephrotoxicity biomarker, kidney injury molecule 1 indicated an accumulation of the molecule in the central lumen of the spheroids. Finally, we tested an approach for an automatic readout of toxicity based on microscopic images with deep learning. Therefore, we created a dataset comprising images of single spheroids, with corresponding labels of the determined cell death rates for training. The algorithm was able to distinguish between three classes of no, mild, and severe treatment effects with a balanced accuracy of 78.7%

Isolation of Single Donors in ZnO

The shallow donor in zinc oxide (ZnO) is a promising semiconductor spin qubit with optical access. Single indium donors are isolated in a commercial ZnO substrate using plasma focused ion beam (PFIB) milling. Quantum emitters are identified optically by spatial and frequency filtering. The indium donor assignment is based on the optical bound exciton transition energy and magnetic dependence. The single donor emission is intensity and frequency stable with a transition linewidth less than twice the lifetime limit. The isolation of optically stable single donors post-FIB fabrication is promising for optical device integration required for scalable quantum technologies based on single donors in direct band gap semiconductors.Comment: E. R. Hansen and V. Niaouris contributed equally to this work. 13 pages, 11 figure

The maize (Zea mays L.) roothairless3 gene encodes a putative GPI-anchored, monocot-specific, COBRA-like protein that significantly affects grain yield

The rth3 (roothairless 3) mutant is specifically affected in root hair elongation. We report here the cloning of the rth3 gene via a PCR-based strategy (amplification of insertion mutagenized sites) and demonstrate that it encodes a COBRA-like protein that displays all the structural features of a glycosylphosphatidylinositol anchor. Genes of the COBRA family are involved in various types of cell expansion and cell wall biosynthesis. The rth3 gene belongs to a monocot-specific clade of the COBRA gene family comprising two maize and two rice genes. While the rice (Oryza sativa) gene OsBC1L1 appears to be orthologous to rth3 based on sequence similarity (86% identity at the protein level) and maize/rice synteny, the maize (Zea mays L.) rth3-like gene does not appear to be a functional homolog of rth3based on their distinct expression profiles. Massively parallel signature sequencing analysis detected rth3 expression in all analyzed tissues, but at relatively low levels, with the most abundant expression in primary roots where the root hair phenotype is manifested.In situ hybridization experiments confine rth3 expression to root hair-forming epidermal cells and lateral root primordia. Remarkably, in replicated field trials involving near-isogenic lines, the rth3 mutant conferred significant losses in grain yield

High-speed photonic crystal modulator with non-volatile memory via structurally-engineered strain concentration in a piezo-MEMS platform

Numerous applications in quantum and classical optics require scalable, high-speed modulators that cover visible-NIR wavelengths with low footprint, drive voltage (V) and power dissipation. A critical figure of merit for electro-optic (EO) modulators is the transmission change per voltage, dT/dV. Conventional approaches in wave-guided modulators seek to maximize dT/dV by the selection of a high EO coefficient or a longer light-material interaction, but are ultimately limited by nonlinear material properties and material losses, respectively. Optical and RF resonances can improve dT/dV, but introduce added challenges in terms of speed and spectral tuning, especially for high-Q photonic cavity resonances. Here, we introduce a cavity-based EO modulator to solve both trade-offs in a piezo-strained photonic crystal cavity. Our approach concentrates the displacement of a piezo-electric actuator of length L and a given piezoelectric coefficient into the PhCC, resulting in dT/dV proportional to L under fixed material loss. Secondly, we employ a material deformation that is programmable under a "read-write" protocol with a continuous, repeatable tuning range of 5 GHz and a maximum non-volatile excursion of 8 GHz. In telecom-band demonstrations, we measure a fundamental mode linewidth = 5.4 GHz, with voltage response 177 MHz/V corresponding to 40 GHz for voltage spanning -120 to 120 V, 3dB-modulation bandwidth of 3.2 MHz broadband DC-AC, and 142 MHz for resonant operation near 2.8 GHz operation, optical extinction down to min(log(T)) = -25 dB via Michelson-type interference, and an energy consumption down to 0.17 nW/GHz. The strain-enhancement methods presented here are applicable to study and control other strain-sensitive systems

Tuning the 3D microenvironment of reprogrammed tubule cells enhances biomimetic modeling of polycystic kidney disease

Renal tubular cells frequently lose differentiation markers and physiological properties when propagated in conventional cell culture conditions. Embedding cells in 3D microenvironments or controlling their 3D assembly by bioprinting can enhance their physiological properties, which is beneficial for modeling diseases in vitro. A potential cellular source for modeling renal tubular physiology and kidney diseases in vitro are directly reprogrammed induced renal tubular epithelial cells (iRECs). iRECs were cultured in various biomaterials and as bioprinted tubular structures. They showed high compatibility with the embedding substrates and dispensing methods. The morphology of multicellular aggregates was substantially influenced by the 3D microenvironment. Transcriptomic analyses revealed signatures of differentially expressed genes specific to each of the selected biomaterials. Using a new cellular model for autosomal-dominant polycystic kidney disease, Pkd1$^{-/-}$ iRECs showed disrupted morphology in bioprinted tubules and a marked upregulation of the Aldehyde dehydrogenase 1a1 (Aldh1a1). In conclusion, 3D microenvironments strongly influence the morphology and expression profiles of iRECs, help to unmask disease phenotypes, and can be adapted to experimental demands. Combining a direct reprogramming approach with appropriate biomaterials will facilitate construction of biomimetic kidney tubules and disease models at the microscale