Genetic Studies of Induced Mutants in \u3ci\u3eMelilotus alba\u3c/i\u3e. I. Short-Internode Dwarf, Curled Leaf, Multifoliolate Leaf, and Cotyledonary Branching

Information obtained from the F1, F2, and F3 generations of crosses between the normal annual M. alba progenitor line and the four mutants, short-internode dwarf, curled leaf, multifoliolate leaf, and cotyledonary branching, indicates that each character is conditioned by a single pair of alleles. The multifoliolate leaf character is dominant over the normal phenotype; the other three mutant characters are recessive. The symbols dw, cl, Mf, and cb are proposed as designations for the respective mutant genes

Blending chitosan-g-poly(caprolactone) with poly(caprolactone) by electrospinning to produce functional fiber mats for tissue engineering applications

Use of electrospun fiber mats for tissue engineering applications has become increasingly prominent. One of the most important polymers in research, poly(ε-caprolactone) (PCL), however, lacks biological performance, easy access to modifications and cellular recognition sites. To improve these properties and to enable further modifications, PCL was blended with chitosan grafted with PCL (CS-g-PCL) and subsequently processed via electrospinning. In this way, chitosan was enriched at the fiber's surface presenting cationic amino groups. The fiber mats were analyzed by various techniques such as scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and X-ray photoelectron spectroscopy (XPS). Furthermore, analyzing thermal properties and crystallinity, showed that an increased content of CS-g-PCL in blend composition leads to a higher overall crystallinity in produced fiber mats. Blending CS-g-PCL into PCL significantly increased initial cellular attachment and proliferation as well as cell vitality, while maintaining adequate mechanical properties, fiber diameter, and interstitial volume. As proof of principle for easy access to further modification, fluorescently labeled alginate (Alg-FA) was attached to the fiber's surface and verified by CLSM. Hence, blending CS-g-PCL with PCL can overcome an inherent weakness of PCL and create bioactive implants for tissue engineering applications. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48650. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc

Array tomography: Characterizing FAC-sorted populations of zebrafish immune cells by their 3D ultrastructure

For 3D reconstructions of whole immune cells from zebrafish, isolated from adult animals by FAC-sorting we employed array tomography on hundreds of serial sections deposited on silicon wafers. Image stacks were either recorded manually or automatically with the newly released ZEISS Atlas 5 Array Tomography platform on a Zeiss FEGSEM. To characterize different populations of immune cells, organelle inventories were created by segmenting individual cells. In addition, arrays were used for quantification of cell populations with respect to the various cell types they contained. The detection of immunological synapses in cocultures of cell populations from thymus or WKM with cancer cells helped to identify the cytotoxic nature of these cells. Our results demonstrate the practicality and benefit of AT for high-throughput ultrastructural imaging of substantial volumes. LAY DESCRIPTION: To look at immune cells from zebrafish we employed array tomography, a technique where arrays of serial sections deposited on solid substrates are used for imaging. Cell populations were isolated from the different organs of zebrafish involved in haematopoiesis, the production of blood cells. They were chemically fixed and centrifuged to concentrate them in a pellet that was then dehydrated and embedded in resin. Using a custom-built handling device it was possible to place hundreds of serial sections on silicon wafers as well ordered arrays. To image a whole cell at a resolution that would allow identifying all the organelles (i.e. compartments surrounded by membranes) inside the cell, stacks of usually 50–100 images were recorded in a scanning electron microscope (SEM). This recording was either done manually or automatically using the newly released Atlas Array Tomography platform on a ZEISS SEM. For the imaging of the sections a pixel size of about 5 nm was chosen, which defines membrane boundaries very well and allows segmentation of the membrane topology. After alignment of the images, cellular components were segmented to locate the individual organelles within the 3D reconstruction of the whole cell and also to create an inventory of organelles. Based on their morphologies we could identify specific cell types in the different hematopoietic organs. We could also quantify the proportion of each cell type in the whole population isolated from a given organ. Some of these specific cells from zebrafish were grown in a culture dish together with human cancer cells. By time-lapse light microscopy we observed that the fish cells attacked the cancer cells and killed them. From this we concluded that these cells must be similar to the cytotoxic cells from humans that play an important role in defence against spontaneously arising cancer cells in our bodies. They form special structures, called immunological synapses that we could also identify on our arrays and reconstruct in 3D. This is the first time the potential of zebrafish immune cells to form immunological synapses has been demonstrated. Our study is a good example for the practicality and benefit of array tomography in high-throughput ultrastructure imaging of substantial volumes, applicable to many areas of cell and developmental biology

The long run relationship between private consumption and wealth : common and idiosyncratic effects

We investigate the long run relationship between private consump- tion, disposable income and wealth approximated by equity and house price indices for a panel of 15 industrialized countries. Consumption, income and wealth are cointegrated in their common components. The impact of house prices exceeds the effect arising from equity wealth. The long run vector is broadly in line with the life cycle permanent income hypothesis, if house prices are allowed to enter the relationship. At the idiosyncratic level, a long run equilibrium is detected between consumption and income, i.e. the wealth variable can be excluded. The income elasticity in the idiosyncratic relationship is significantly less than unity. Hence, the presence of wealth effects in consumption equations arises from the international integration of asset markets and points to the relevance of risk sharing activities of agents. Without sufficient opportunities, an increase in national saving rates would be expected, leading to a lower path of private consumption expenditures.info:eu-repo/semantics/publishedVersio