Genomic Architecture of Phenotypic Plasticity in Response to Water Stress in Tetraploid Wheat

Phenotypic plasticity is one of the main mechanisms of adaptation to abiotic stresses via changes in critical developmental stages. Altering flowering phenology is a key evolutionary strategy of plant adaptation to abiotic stresses, to achieve the maximum possible reproduction. The current study is the first to apply the linear regression residuals as drought plasticity scores while considering the variation in flowering phenology and traits under non-stress conditions. We characterized the genomic architecture of 17 complex traits and their drought plasticity scores for quantitative trait loci (QTL) mapping, using a mapping population derived from a cross between durum wheat (Triticum turgidum ssp. durum) and wild emmer wheat (T. turgidum ssp. dicoccoides). We identified 79 QTLs affected observed traits and their plasticity scores, of which 33 reflected plasticity in response to water stress and exhibited epistatic interactions and/or pleiotropy between the observed and plasticity traits. Vrn-B3 (TaTF1) residing within an interval of a major drought-escape QTL was proposed as a candidate gene. The favorable alleles for most of the plasticity QTLs were contributed by wild emmer wheat, demonstrating its high potential for wheat improvement. Our study presents a new approach for the quantification of plant adaptation to various stresses and provides new insights into the genetic basis of wheat complex traits under water-deficit stress.     

Screening Collagenase Activity in Bacterial Lysate for Directed Enzyme Applications

Collagenases are essential enzymes capable of digesting triple-helical collagen under physiological conditions. These enzymes play a key role in diverse physiological and pathophysiological processes. Collagenases are used for diverse biotechnological applications, and it is thus of major interest to identify new enzyme variants with improved characteristics such as expression yield, stability, or activity. The engineering of new enzyme variants often relies on either rational protein design or directed enzyme evolution. The latter includes screening of a large randomized or semirational genetic library, both of which require an assay that enables the identification of improved variants. Moreover, the assay should be tailored for microplates to allow the screening of hundreds or thousands of clones. Herein, we repurposed the previously reported fluorogenic assay using 3,4-dihydroxyphenylacetic acid for the quantitation of collagen, and applied it in the detection of bacterial collagenase activity in bacterial lysates. This enabled the screening of hundreds of E. coli colonies expressing an error-prone library of collagenase G from C. histolyticum, in 96-well deep-well plates, by measuring activity directly in lysates with collagen. As a proof-of-concept, a single variant exhibiting higher activity than the starting-point enzyme was expressed, purified, and characterized biochemically and computationally. This showed the feasibility of this method to support medium-high throughput screening based on direct evaluation of collagenase activity.     

Temporal analysis of net fluvial methylmercury loading in a dystrophic and a clear water lake

The concentration of methylmercury (MeHg) in aquatic ecosystems is the net result of the highly dynamic abiotic and biotic processes of mercury methylation and demethylation. In this study, we conduct an examination of the net fluvial loading of methylmercury (MeHg_Net = MeHg_Watershed − MeHg_{Lake outflow}) across a 3 year time frame in both a dystrophic lake and an oligotrophic lake. A significant portion of MeHg_Net variance in both lakes could be attributed to a seasonal pattern (11.4%, p = 0.009; oligotrophic, and 27.0%, p < 0.0001; dystrophic) which in both cases, was most correlated with air temperature. The dystrophic lake appeared to be a net source of methylmercury (MeHg_Net = − 1.9 ± 0.3 mg MeHg d^− 1) while the oligotrophic lake appeared to be a net sink (MeHg_Net = 0.4 ± 0.2 mg MeHg d^− 1), indicating that there was net methylation in the dystrophic lake and net demethylation in the oligotrophic lake. Higher MeHg loading to the lakes occurred during the summer and between seasons there was a difference in MeHg_Net of 1.1 ±0.3 mg MeHg d^− 1 and 3.1 ± 0.6 mg MeHg d^− 1. Seasonal patterns of MeHg_Net in the oligotrophic lake lagged behind the dystrophic lake by 39 days. The short term variation in MeHg_Net was dominated by precipitation (t = 2.73, p = 0.008; dystrophic, t = 2.53, p = 0.017; oligotrophic).     

Size selectivity during dip coating of sol–gel silica-based antireflective coatings and its effect on the porosity of the coatings

The behavior of the particle size distribution (PSD) during the preparation of sol–gel silica-based antireflective coatings (ARCs) by dip coating was examined. It was found that the PSD after deposition differs dramatically from the PSD in the sol–gel suspensions, with the PSD after deposition being much narrower. A correlation between a decrease in the porosity of the ARC and an increase in the dispersity of the deposited PSD was also found. Hence, controlling the PSD during deposition has a direct effect on the resulting porosity and thus on the reflectance of an ARC. It was found that the temperature and deposition speed during dip coating, respectively, have very little effect on the deposited PSD. It was found that the PSD of the sol–gel suspension control the content of the deposited PSD, but does not change the range of sizes deposited. Finally, it was found that random-uniform particle placement results in elongated sequences of four or more particles, which supports our previous conclusion that the linear permittivity mixing rule is most appropriate for Stöber-based ARCs.     

Digital collaborative learning in elementary and middle schools as a function of individualistic and collectivistic culture: The role of ICT coordinators' leadership experience,students' collaboration skills,and sustainability

The purpose of this study was to examine the influence of online collaborative learning experiences on students' digital collaboration skills and on the sustainability of e-collaboration in schools' culture—comparing individualistic versus collectivistic cultures. In addition, we explored how the leadership experience of schools' ICT coordinators was predicted by their sense of professionalism and cognitive, emotional and social aspects of perceived learning (PL), while leading the collaborative projects. The participants were ICT coordinators from 513 Israeli schools; 214 of whom were Hebrew-speakers, and 299 Arabic-speakers. The participants were asked to complete an online questionnaire, which included multiple-choice and open-ended questions. The results showed significant differences between a variety of the coordinator-related variables as a function of learning culture (more individualistic vs.more collectivistic). Coordinators' leadership experience was a powerful predictor of students' digital collaboration skills, but did not predict the sustainability of e-collaboration. Coordinators' emotional PL predicted the sustainability of collaboration in both schools with more individualistic and with more collectivistic learning cultures. The implications of the findings for educational theory and practise are discussed.     

A Theory of Causal Learning in Children: Causal Maps and Bayes Nets.

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computations similar to those for learning causal Bayes nets and for predicting with them. Experimental results suggest that 2- to 4-year-old children construct new causal maps and that their learning is consistent with the Bayes net formalism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Toward evidence-based interventions for diverse populations: The San Francisco General Hospital prevention and treatment manuals.

Clinical trials have seldom included adequate samples of people of color. Therefore, practitioners serving ethnic minorities often do not have access to readily available evidence-based interventions. This article summarizes the development and empirical evaluation of prevention and treatment manuals designed for low-income ethnic minority populations at San Francisco General Hospital. The manuals were often designed by people of color familiar with the communities for which they were developed. Independent research teams in multi-site national and international clinical trials have evaluated many of these manuals with encouraging results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From tip-of-the-tongue (TOT) data to theoretical implications in two steps: When more TOTs means better retrieval.

Two experiments in which participants named pictured objects with difficult or easier names, and a reanalysis and review of published data, reveal that problematic measures used in previous studies obscured the implications of group differences in tip-of-the-tongue (TOT) rates. In Experiment 1, increased age led to more TOTs for difficult but not easy targets. In Experiment 2, bilinguals had more TOTs than monolinguals for easy targets but fewer TOTs for difficult targets. The authors developed a theoretically motivated measure that clarifies the implications of TOT data by linking all responses elicited in the TOT paradigm with either success or failure in completing 2 retrieval steps in current models of language production. The 2-step analysis reveals a common mechanism for the age and bilingualism effects and implies that age has both positive and negative effects on retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new transboundary freshwater dispute before the International Court of Justice

On 6 June 2016 Chile submitted its long-standing dispute with Bolivia concerning the Silala/Siloli watercourse to the International Court of Justice. Since 1997 Bolivia has contended that the watercourse is not international and that it therefore belongs exclusively to Bolivia. In its application, Chile requested that the court “declare that the Silala River system is in fact and in law an international watercourse whose use by Chile and Bolivia is governed by customary international law”. This case has the potential to produce a landmark decision in the international water law field since it is the first time that a dispute concerning the status of a watercourse as international has been submitted to the court. If the court finds that the Silala/Siloli is indeed an international watercourse, it will have a unique opportunity to clarify states’ substantive and procedural obligations with respect to its use.     

A Recombinant Collagen–mRNA Platform for Controllable Protein Synthesis

We have developed a collagen–mRNA platform for controllable protein production that is intended to be less prone to the problems associated with commonly used mRNA therapy as well as with collagen skin‐healing procedures. A collagen mimic was constructed according to a recombinant method and was used as scaffold for translating mRNA chains into proteins. Cysteines were genetically inserted into the collagen chain at positions allowing efficient ribosome translation activity while minimizing mRNA misfolding and degradation. Enhanced green fluorescence protein (eGFP) mRNA bound to collagen was successfully translated by cell‐free Escherichia coli ribosomes. This system enabled an accurate control of specific protein synthesis by monitoring expression time and level. Luciferase–mRNA was also translated on collagen scaffold by eukaryotic cell extracts. Thus we have demonstrated the feasibility of controllable protein synthesis on collagen scaffolds by ribosomal machinery.