Cancer stem cells revisited

© 2017 Nature America, Inc., part of Springer Nature. All rights reserved. The cancer stem cell (CSC) concept was proposed four decades ago, and states that tumor growth, analogous to the renewal of healthy tissues, is fueled by small numbers of dedicated stem cells. It has gradually become clear that many tumors harbor CSCs in dedicated niches, and yet their identification and eradication has not been as obvious as was initially hoped. Recently developed lineage-tracing and cell-ablation strategies have provided insights into CSC plasticity, quiescence, renewal, and therapeutic response. Here we discuss new developments in the CSC field in relationship to changing insights into how normal stem cells maintain healthy tissues. Expectations in the field have become more realistic, and now, the first successes of therapies based on the CSC concept are emerging

Polarizing intestinal epithelial cells electrically through Ror2

© 2014. Published by The Company of Biologists Ltd.Peer reviewedPublisher PD

A new lab facility for measuring bidirectional reflectance/emittance distribution functions of soils and canopies

Recently, a laboratory measurement facility has been realized for assessing the anisotropic reflectance and emittance behaviour of soils, leaves and small canopies under controlled illumination conditions. The facility consists of an ASD FieldSpec 3 spectroradiometer covering the spectral range from 350 – 2500 nm at 1 nm spectral sampling interval. The spectroradiometer is deployed using a fiber optic cable with either a 1°, 8° or 25° instantaneous field of view (IFOV). These measurements can be used to assess the plant pigment (chlorophyll, xanthophyll, etc.) and non-pigment system (water, cellulose, lignin, nitrogen, etc.). The thermal emittance is measured using a NEC TH9100 Infrared Thermal Imager. It operates in a single band covering the spectral range from 8 – 14 mm with a resolution of 0.02 K. Images are 320 (H) by 240 (V) pixels with an IFOV of 1.2 mrad. A 1000 W Quartz Tungsten Halogen (QTH) lamp is used as illumination source, approximating the radiance distribution of the sun. This one is put at a fixed position during a measurement session. Multi-angular measurements are achieved by using a robotic positioning system allowing to perform either reflectance or emittance measurements over almost a complete hemisphere. The hemisphere can be sampled continuously between 0° and 80° from nadir and up to a few degrees from the hot-spot configuration (depending on the IFOV of the measurement device) for a backscattering target. Measurement distance to targets can be varied between 0.25 and 1 m, although with a distance of more than 0.6 m it is not possible to cover the full hemisphere. The goal is to infer the BRDF (bidirectional reflectance distribution function) and BTDF (bidirectional thermal distribution function) from these multi-angular measurements for various surface types (like soils, agricultural crops, small tree canopies and artificial objects) and surface roughness. The steering of the robotic arm and the reading of the spectroradiometer and the thermal camera are all fully automated

A high-resolution and harmonized model approach for reconstructing and analysing historic land changes in Europe

Human-induced land use changes are nowadays the second largest contributor to atmospheric carbon dioxide after fossil fuel combustion. Existing historic land change reconstructions on the European scale do not sufficiently meet the requirements of greenhouse gas (GHG) and cli- mate assessments, due to insufficient spatial and thematic detail and the consideration of various land change types. This paper investigates if the combination of different data sources, more detailed modelling techniques, and the inte- gration of land conversion types allow us to create accu- rate, high-resolution historic land change data for Europe suited for the needs of GHG and climate assessments. We validated our reconstruction with historic aerial photographs from 1950 and 1990 for 73 sample sites across Europe and compared it with other land reconstructions like Klein Gold- ewijk et al. (2010, 2011), Ramankutty and Foley (1999), Pon- gratz et al. (2008) and Hurtt et al. (2006). The results indicate that almost 700 000km2 (15.5%) of land cover in Europe has changed over the period 1950–2010, an area similar to France. In Southern Europe the relative amount was almost 3.5% higher than average (19 %). Based on the results the specific types of conversion, hot-spots of change and their relation to political decisions and socio-economic transitions were studied. The analysis indicates that the main drivers of land change over the studied period were urbanization, the reforestation program resulting from the timber shortage af- ter the Second World War, the fall of the Iron Curtain, the Common Agricultural Policy and accompanying afforesta- tion actions of the EU. Compared to existing land cover re- constructions, the new method considers the harmonization of different datasets by achieving a high spatial resolution and regional detail with a full coverage of different land cat- egories. These characteristics allow the data to be used to support and improve ongoing GHG inventories and climate research

Ефективність симбіотичної азотфіксації в агроценозах України

Проведено порівняльну оцінку ефективності виробничих і перспективних штамів бульбочкових бактерій колекції Південної дослідної станції ІСГМ УААН у симбіозі з сучасними сортами бобових культур. Визначені високоефективні комбінації “сорти – штами”. Показано доцільність передпосівної інокуляції насіння бобових культур на фоні ґрунтової популяції ризобій.Проведена сравнительная оценка эффективности производственных и перспективных штаммов клубеньковых бактерий коллекции Южной опытной станции ИСХМ УААН в симбиозе с современными сортами бобовых культур. Определены высокоэффективные комбинации “сорта – штаммы”. Показана целесообразность предпосевной инокуляции семян бобовых культур на фоне почвенной популяции ризобий.The comparative estimation of rhisobia strains (from the collection of the Southern Experimental Station of Institute of Agricultural Microbiology UAAS) efficiency in symbiosis with modern legume cultivars was done. Highly effective complemented „cultivars – strains” combinations have been determined. It was shown the expediency of legume seeds pre-sowing treatment on background of soil rhisobia population

A new setup to measure bidirectional reflectance distribution functions

The Plant Facility, a new laboratory goniometer system, built by the Wageningen University has been tested in order to take bidirectional reflectance distribution function (BRDF) measurements. An ASD FieldSpec 3 spectroradiometer mounted on an industrial robot arm is able to measure small targets over the full hemispherical dome. Due to the fast acquisition time it is a promising setup for BRDF measurements of natural targets. In this paper, the preliminary results of BRDF measurements of freshly grown watercress and lawn grass are presented. The results show that both watercress and lawn grass show anisotropic behavior and that LAI plays an important role

Ascl2-Dependent Cell Dedifferentiation Drives Regeneration of Ablated Intestinal Stem Cells

Ablation of LGR5+ intestinal stem cells (ISCs) is associated with rapid restoration of the ISC compartment. Different intestinal crypt populations dedifferentiate to provide new ISCs, but the transcriptional and signaling trajectories that guide this process are unclear, and a large body of work suggests that quiescent “reserve” ISCs contribute to regeneration. By timing the interval between LGR5+ lineage tracing and lethal injury, we show that ISC regeneration is explained nearly completely by dedifferentiation, with contributions from absorptive and secretory progenitors. The ISC-restricted transcription factor ASCL2 confers measurable competitive advantage to resting ISCs and is essential to restore the ISC compartment. Regenerating cells re-express Ascl2 days before Lgr5, and single-cell RNA sequencing (scRNA-seq) analyses reveal transcriptional paths underlying dedifferentiation. ASCL2 target genes include the interleukin-11 (IL-11) receptor Il11ra1, and recombinant IL-11 enhances crypt cell regenerative potential. These findings reveal cell dedifferentiation as the principal means for ISC restoration and highlight an ASCL2-regulated signal that enables this adaptive response