Initial Impact of the Gabíkovo Hydroelectric Scheme on the Species Richness and Composition of 0+ Fish Assemblages in the Slovak Flood Plain, River Danube

Relatively little information exists on the effects of hydroelectric schemes on 0+ fish composition in large European rivers because few or no pre-impact data exist. We compared 0+ fish species richness and composition, relative density, fish size as well as available and used habitat using data from 12 floodplain sites sampled just prior to (1992) and four years after (1996) the start of operations of the Gabíkovo hydropower station on the River Danube (Slovakia). We also used modelling techniques to assess the change in species richness and habitat use and to predict 1996 occurrences from the 1992 data set. The floodplain was greatly modified by the hydroscheme. Only 12 of 27 sites sampled in August 1992 were extant in August 1996. Therefore, all four channel types identified (flowing, abandoned, weir, wing-dam) were more lentic in 1996 than in 1992, with increased width, smaller-sized sediment (silt, clay) and greater amounts of macrophytes. After the operations of the hydroscheme, the overall relative density of fishes (individuals per surface area) of all ages decreased, with the exception of 0+ fishes, despite a slight reduction in 0+ fish density in all channel types except weirs. Species number increased from 25 to 28, although in all channel types there was a change in the composition of the 0+ fish assemblages, with rheophiles generally replaced by limnophiles and migrants from the lower Danube. The two most important microhabitat variables were the proportion of macrophytes and gravel, the latter being the factor distinguishing 0+ fish microhabitat use in 1992 (preferences) and 1996 (indifference or avoidance). Species richness and 0+ fish density in 1996 could be predicted from the 1992 data using simple log-linear models (density, richness, sample number). Species-specific occurrence in 1996 could not be predicted using environmental/fish data from 1992 with multiple regression or generalized additive models (GAM). However, the overall GAM from 1992 could predict overall fish occurrence in 1996

IDSS Country Study Ireland - Study on integrated delivery of social services aiming at the activation of minimum income recipients in the labour market

The abstract is included in the text

NanoBiT ‐ and NanoBiT/BRET ‐based assays allow the analysis of binding kinetics of Wnt‐3a to endogenous Frizzled 7 in a colorectal cancer model

Background and Purpose Wnt binding to Frizzleds (FZD) is a crucial step that leads to the initiation of signalling cascades governing multiple processes during embryonic development, stem cell regulation and adult tissue homeostasis. Recent efforts have enabled us to shed light on Wnt–FZD pharmacology using overexpressed HEK293 cells. However, assessing ligand binding at endogenous receptor expression levels is important due to differential binding behaviour in a native environment. Here, we study FZD paralogue, FZD$_{7}$, and analyse its interactions with Wnt-3a in live CRISPR-Cas9-edited SW480 cells typifying colorectal cancer. Experimental Approach SW480 cells were CRISPR-Cas9-edited to insert a HiBiT tag on the N-terminus of FZD$_{7}$, preserving the native signal peptide. These cells were used to study eGFP-Wnt-3a association with endogenous and overexpressed HiBiT-FZD$_{7}$ using NanoBiT/bioluminescence resonance energy transfer (BRET) and NanoBiT to measure ligand binding and receptor internalization. Key Results With this new assay the binding of eGFP-Wnt-3a to endogenous HiBiT-FZD$_{7}$ was compared with overexpressed receptors. Receptor overexpression results in increased membrane dynamics, leading to an apparent decrease in binding on-rate and consequently in higher, up to 10 times, calculated Kd. Thus, measurements of binding affinities to FZD$_{7}$ obtained in overexpressed cells are suboptimal compared with the measurements from endogenously expressing cells. Conclusions and Implications Binding affinity measurements in the overexpressing cells fail to replicate ligand binding affinities assessed in a (patho)physiologically relevant context where receptor expression is lower. Therefore, future studies on Wnt–FZD$_{7}$ binding should be performed using receptors expressed under endogenous promotion

Class Frizzled GPCRs in GtoPdb v.2025.3

Receptors of the Class Frizzled (FZD, nomenclature as agreed by the NC-IUPHAR subcommittee on the Class Frizzled GPCRs [184]), are GPCRs highly conserved across species and were originally identified in Drosophila [21]. While SMO shows structural resemblance to the 10 FZDs, it is functionally separated as it is involved in Hedgehog signaling [184]. SMO exerts its effects by activating heterotrimeric G proteins or stabilization of GLI by sequestering catalytic PKA subunits [191, 6, 62]. While SMO itself is bound by sterols and oxysterols [28, 96], FZDs are activated by WNTs, which are cysteine-rich lipoglycoproteins with fundamental functions in ontogeny and tissue homeostasis. FZD signaling was initially divided into two pathways, being either dependent on the accumulation of the transcription regulator β-catenin or being β-catenin-independent (often referred to as canonical vs. non-canonical WNT/FZD signaling, respectively). Nevertheless, it makes pharmacologically more sense to define downstream signaling by transducer coupling to either DVL or heterotrimeric G proteins [185]. WNT stimulation of FZDs can, in cooperation with the low density lipoprotein receptors LRP5 (O75197) and LRP6 (O75581), lead to the inhibition of a constitutively active destruction complex, which results in the accumulation of β-catenin and subsequently its translocation to the nucleus. β-catenin, in turn, modifies gene transcription by interacting with TCF/LEF transcription factors. WNT/β-catenin-dependent signalling can also be activated by FZD subtype-specific WNT surrogates [142]. β-catenin-independent FZD signalling is far more complex with regard to the diversity of the activated pathways. WNT/FZD signalling can lead to the activation of heterotrimeric G proteins [35, 188, 159], the elevation of intracellular calcium [194], activation of cGMP-specific PDE6 [2] and elevation of cAMP as well as RAC-1, JNK, Rho and Rho kinase signalling [61]. Novel resonance energy transfer-based tools have allowed the study of the GPCR-like nature of FZDs in greater detail. Upon ligand stimulation, FZDs undergo conformational changes and signal via heterotrimeric G proteins [248, 249, 110, 183, 108, 56, 13]. Furthermore, the phosphoprotein Dishevelled constitutes a key transducer in WNT/FZD signaling towards planar-cell-polarity-like pathways. Importantly, FZDs adopt distinct conformational landscapes that regulate pathway selection [249, 54]. As with other GPCRs, members of the Frizzled family are functionally dependent on the arrestin scaffolding protein for internalization [24], as well as for β-catenin-dependent [15] and -independent [93, 16] signalling. The pattern of cell signalling is complicated by the presence of additional ligands, which can enhance or inhibit FZD signalling (secreted Frizzled-related proteins (sFRP), Wnt-inhibitory factor (WIF), sclerostin or Dickkopf (DKK)), as well as modulatory (co)-receptors with Ryk, ROR1, ROR2 and PTK7, which may also function as independent signaling proteins. An important FZD4-selective non-WNT agonist is the norrin cysteine knot protein, which is a key player in FZD4-mediated vascularization for example in the retina and which is functionally related to familial exudative vitreoretinopathy (FEVR)

Flexible or Secure Jobs?: Young Workers and Internships in Ireland and Spain

Over the last decades, European countries have increasingly relied on Active Labor Market Policies (ALMPs) as a mechanism to increase the employability of the unemployed. Following the 2008 economic crisis, ALMPs were increasingly relied on by Ireland and Spain as a strategy to assist and improve unemployed young workers’ integration into the labor market. One notable aspect was the Irish and Spanish government’s development of new ALMP internship programs, ones that relied more extensively on demand led activation through firm work experience or ALMP internships. While the development of these ALMP internship programs was in line with the existing ALMP evaluation literature which asserted higher levels of employer integration yielded higher probabilities for employment (Kluve 2006; Card et al. 2009), none of the evaluation literature considered the role of the employer in shaping ALMP outcomes, nor did it consider other aspects of job quality outcomes beyond earnings. While adopting a comparative case study design at the sectoral level within five Irish and Spanish ICT firms, this thesis aims to understand how Irish and Spanish ALMP internships facilitate particular job quality outcomes within the Spanish and Irish ICT sectors. Through an examination of the key macro and meso institutions within which these ICT firms are embedded, the research identifies and examines how particular mechanisms may enable or constrain the ICT firms’ behavior surrounding job quality outcomes through ALMP internships. It provides a conceptualization of job quality through the adoption of a flexicurity framework which enables the examination of four job quality dimensions: earnings, working time quality, skills and discretion and prospects and internal progression. The analysis reveals that in a context of weak macro and meso level institutions, firm features play an increasingly important role in explaining how employers facilitate particular job quality outcomes through ALMP internships within the Spanish and Irish ICT sectors. Within this weak institutional environment, similar patterns were found among the Irish and Spanish MNC subsidiary firms and the Irish and Spanish domestic firms in relation to how these two groups of firms used ALMP internships. The MNC subsidiary firms were found to primarily use ALMP internships as a flexible supply of labor, one with limited scope for upskilling. In comparison, among the domestic ICT firms, the ALMP internships were more effective, given the reduced hiring risks provided and the access ALMP interns had to a wider range of skill development and work experience, thus providing for upskilling. This thesis highlights how sectoral and firm specific dynamics may influence employer behavior related to job quality outcomes through ALMP internships. In doing so, it also emphasizes the need for further institutional constraints that encourage ‘good’ job quality outcomes among Irish and Spanish firms that recruit through ALMP internships