Facilitating the conservation treatment of Eva Hesse's Addendum through practice-based research, including a comparative evaluation of novel cleaning systems

Abstract This paper describes the methodology and practice-based research underpinning the development of a successful cleaning strategy for Eva Hesse's sculpture Addendum (1967, Tate Collection T02394). Research strands included: technical and art historical investigations to determine the materials and construction of the work of art and to define the aims of the conservation treatment; the production, soiling and accelerated ageing of mock-up samples using contemporary equivalent materials; and the systematic, iterative evaluation of soiling removal systems, which were further refined for appropriate use on the work of art. The comparative cleaning system evaluation was employed to determine options which offered optimal soiling removal efficacy and posed minimal risk to the work of art. Newly developed Nanorestore Gel® Peggy series (i.e. polyvinyl alcohol (PVA) and polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP)-based hydrogels), designed for the cleaning of modern and contemporary art, were evaluated with a range of other gels, emulsifiers and cosmetic sponges and assessed through a combination of empirical observation, microscopy and spectroscopic techniques. Promising options, combined with tailored aqueous phases derived from trials on mock-up samples, were then evaluated on discreet areas of the sculpture. After extensive testing, the top papier mâché section of Addendum was surface cleaned using an aqueous solution applied with cosmetic sponges, and the ropes were surface cleaned using a modified version of Nanorestore Gel® Peggy 5 (PVA/PVP) loaded with a tailored aqueous solution. The optimisation of this hydrogel, combined with the extensive supporting research, enabled the successful, low-risk, conservation treatment of Addendum for the first time since acquisition

The myxozoan parasite Myxobolus bejeranoi (Cnidaria: Myxozoa) infection dynamics and host specificity in hybrid tilapia aquaculture

Nile × blue tilapia hybrid (Oreochromis niloticus × O. aureus) has become an important food fish in intensive freshwater aquaculture. Recently, the parasite Myxobolus bejeranoi (Cnidaria: Myxozoa) was found to infect hybrid tilapia gills at high prevalence, causing immune suppression and high mortality. Here, we explored additional characteristics of M. bejeranoi–tilapia interaction, which enable efficient proliferation of this parasite inside its specific host. Highly sensitive quantitative polymerase chain reaction (qPCR) and in situ hybridization analyses of fry collected from fertilization ponds provided evidence to an early-life infection of fish by a myxozoan parasite, occurring less than 3 weeks post-fertilization. Because Myxobolus species are highly host-specific, we next compared infection rates in hybrid tilapia and in both its parental species following a 1-week exposure to infectious pond water. Analysis by qPCR and histological sections showed that while blue tilapia was as susceptible to M. bejeranoi as the hybrid, Nile tilapia appeared to be resistant. This is the first report of differential susceptibility of a hybrid fish vs its parental purebreds to a myxozoan parasite. These findings advance our understanding of the relationship between M. bejeranoi and tilapia fish and raise important questions regarding the mechanisms that allow the parasite to distinguish between very closely related species and to infect a specific organ at very early-life stages

Increased songbird nest depredation due to Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland

Abstract Background In recent decades, a decrease of passerine densities was documented in Mediterranean shrublands. At the same time, a widespread encroachment of Aleppo pines (Pinus halepensis) to Mediterranean shrubland occurred. Such changes in vegetation structure may affect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assessing the effects of Aleppo pine encroachment on Sardinian warbler (Sylvia melanocephala) nest depredation in Mediterranean shrublands. We examined direct and indirect predation pressures through a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay (Garrulus glandarius) behaviour as indirect evidence of predation risk. Results We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in mixed shrubland and pines. These areas are suitable for warblers but had high occurrence rate of Eurasian jays. Conclusions Encroaching pines directly increase activity of Eurasian jays in shrubland habitats, which reduced the nesting success of Sardinian warblers. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of predators and decrease the predation pressure on passerine nests

Infection by the Parasite <i>Myxobolus bejeranoi</i> (Cnidaria: Myxozoa) Suppresses the Immune System of Hybrid Tilapia

Myxozoa (Cnidaria) is a large group of microscopic obligate endoparasites that can cause emerging diseases, affecting wild fish populations and fisheries. Recently, the myxozoan Myxobolus bejeranoi was found to infect the gills of hybrid tilapia (Nile tilapia (Oreochromis niloticus) × Jordan/blue tilapia (O. aureus)), causing high morbidity and mortality. Here, we used comparative transcriptomics to elucidate the molecular processes occurring in the fish host following infection by M. bejeranoi. Fish were exposed to pond water containing actinospores for 24 h and the effects of minor, intermediate, and severe infections on the sporulation site, the gills, and on the hematopoietic organs, head kidney and spleen, were compared. Enrichment analysis for GO and KEGG pathways indicated immune system activation in gills at severe infection, whereas in the head kidney a broad immune suppression included deactivation of cytokines and GATA3 transcription factor responsible for T helper cell differentiation. In the spleen, the cytotoxic effector proteins perforin and granzyme B were downregulated and insulin, which may function as an immunomodulatory hormone inducing systemic immune suppression, was upregulated. These findings suggest that M. bejeranoi is a highly efficient parasite that disables the defense mechanisms of its fish host hybrid tilapia

Proteomic analysis of the parasitic Cnidarian Ceratonova shasta (Cnidaria: Myxozoa) reveals diverse roles of actin in motility and spore formation

Myxozoans are widely distributed aquatic obligate endoparasites that were recently recognized as belonging within the phylum Cnidaria. They have complex life cycles with waterborne transmission stages: resistant, infectious spores that are unique to myxozoans. However, little is known about the processes that give rise to these transmission stages. To understand the molecular underpinnings of spore formation, we conducted proteomics on Ceratonova shasta, a highly pathogenic myxozoan that causes severe mortalities in wild and hatchery-reared salmonid fishes. We compared proteomic profiles between developmental stages from inside the fish host, and the mature myxospore, which is released into the water where it drifts passively, ready to infect the next host. We found that C. shasta contains 2,123 proteins; representing the first proteomic catalog of a myxozoan myxospore. Analysis of proteins differentially expressed between developing and mature spore stages uncovered processes that are active during spore formation. Our data highlight dynamic changes in the actin cytoskeleton, which provides myxozoan developmental stages with mobility through lamellipodia and filopodia, whereas in the mature myxospore the actin network supports F-actin stabilization that reinforces the transmission stage. These findings provide molecular insight into the myxozoan life cycle stages and, particularly, into the process of sporogenesis.Fil: Brekhman, Vera. University Of Haifa; IsraelFil: Ofek Lalzar, Maya. University Of Haifa; IsraelFil: Atkinson, Stephen D.. State University of Oregon; Estados UnidosFil: Alama Bermejo, Gema. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina. State University of Oregon; Estados Unidos. Institute of Parasitology. Biology Centre of the Czech Academy of Sciences; República ChecaFil: Maor Landaw, Keren. University Of Haifa; IsraelFil: Malik, Assaf. University Of Haifa; IsraelFil: Bartholomew, Jerri. State University of Oregon; Estados UnidosFil: Lotan, Tamar. University Of Haifa; Israe

The Molecular Mechanisms Employed by the Parasite <i>Myxobolus bejeranoi</i> (Cnidaria: Myxozoa) from Invasion through Sporulation for Successful Proliferation in Its Fish Host

Myxozoa is a unique group of obligate endoparasites in the phylum Cnidaria that can cause emerging diseases in wild and cultured fish populations. Recently, we identified a new myxozoan species, Myxobolus bejeranoi, which infects the gills of cultured tilapia while suppressing host immunity. To uncover the molecular mechanisms underlying this successful parasitic strategy, we conducted transcriptomics analysis of M. bejeranoi throughout the infection. Our results show that histones, which are essential for accelerated cell division, are highly expressed even one day after invasion. As the infection progressed, conserved parasitic genes that are known to modulate the host immune reaction in different parasitic taxa were upregulated. These genes included energy-related glycolytic enzymes, as well as calreticulin, proteases, and miRNA biogenesis proteins. Interestingly, myxozoan calreticulin formed a distinct phylogenetic clade apart from other cnidarians, suggesting a possible function in parasite pathogenesis. Sporogenesis was in its final stages 20 days post-exposure, as spore-specific markers were highly expressed. Lastly, we provide the first catalog of transcription factors in a Myxozoa species, which is minimized compared to free-living cnidarians and is dominated by homeodomain types. Overall, these molecular insights into myxozoan infection support the concept that parasitic strategies are a result of convergent evolution

AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process

National Multicenter Study of Predictors and Outcomes of Bacteremia upon Hospital Admission Caused by Enterobacteriaceae Producing Extended-Spectrum β-Lactamases ▿

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are pathogens that may lead to a spectrum of clinical syndromes. We aimed to identify predictors and outcomes of ESBL bacteremia upon hospital admission (UHA) in a nationwide prospective study. Thus, a multicenter prospective study was conducted in 10 Israeli hospitals. Adult patients with bacteremia due to Enterobacteriaceae diagnosed within 72 h of hospitalization were included. Patients with ESBL producers (cases) were compared to those with non-ESBL producers (controls), and a 1:1 ratio was attempted in each center. A case-control study to identify predictors and a cohort study to identify outcomes were conducted. Bivariate and multivariate logistic regressions were used for analyses. Overall, 447 patients with bacteremia due to Enterobacteriaceae were recruited: 205 cases and 242 controls. Independent predictors of ESBL were increased age, multiple comorbid conditions, poor functional status, recent contact with health care settings, invasive procedures, and prior receipt of antimicrobial therapy. In addition, patients presenting with septic shock and/or multiorgan failure were more likely to have ESBL infections. Patients with ESBL producers suffered more frequently from a delay in appropriate antimicrobial therapy (odds ratio [OR], 4.7; P, <0.001) and had a higher mortality rate (OR, 3.5; P, <0.001). After controlling for confounding variables, both ESBL production (OR, 2.3; P, 9.1) and a delay in adequate therapy (OR, 0.05; P, 0.001) were significant predictors for mortality and other adverse outcomes. We conclude that among patients with bacteremia due to Enterobacteriaceae UHA, those with ESBL producers tend to be older and chronically ill and to have a delay in effective therapy and severe adverse outcomes. Efforts should be directed to improving the detection of patients with ESBL bacteremia UHA and to providing immediate appropriate therapy

Dimerization of the ARF2A protein and its interaction.

<p>ARF2A was cloned downstream of the DNA-binding domain (DB-ARF2A) and co-transformed into yeast with either (A) ARF2A cloned downstream of the activation domain (AD-ARF2A); or (B) ASR1 cloned downstream of the activation domain (AD-ASR1), yeast growth on media lacking leucine, tryptophan, histidine and adenine indicated positive protein-protein interactions. (C) Relative expression levels of <i>ASR1</i> in WT cv. MicroTom fruit at five developmental stages (IG: immature green; MG: mature green; Br: breaker; Or: orange; and R: red), error bars represent SE; statistical significance was evaluated using an ANOVA test (JMP software, SAS) with three biological repeats based on the average of three technical replicates, values indicated by the same letter (a,b,c) are not statistically significant, p-value<0.05. (D) A Bimolecular Fluorescence Complementation assay (BiFC) was carried out by transient expression in tobacco leaves; ARF2A was cloned downstream of the amino-terminal region of YFP (yellow fluorescent protein; YN-ARF2A) and ASR1 was cloned downstream of the carboxy-terminal region of YFP (YC-ASR1); leaf regions were examined for fluorescent signal by light and confocal fluorescence microscopy. Inset zoom region shows that the ARF2A-ASR1 interaction is nuclear localized. Scale bars in the light and confocal fluorescence microscopy represent 50 μm and 10 μm, respectively.</p