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A water soluble fluorescent polymer as a dual colour sensor for temperature and a specific protein
(2013)
We present two thermoresponsive water soluble copolymers prepared via free radical statistical copolymerization of N-isopropylacrylamide (NIPAm) and of oligo(ethylene glycol) methacrylates (OEGMAs), respectively, with a solvatochromic 7-(diethylamino)-3-carboxy-coumarin (DEAC)- functionalized monomer. In aqueous solutions, the NIPAm-based copolymer exhibits characteristic changes in its fluorescence profile in response to a change in solution temperature as well as to the presence of a specific protein, namely an anti-DEAC antibody. This polymer emits only weakly at low temperatures, but exhibits a marked fluorescence enhancement accompanied by a change in its emission colour when heated above its cloud point. Such drastic changes in the fluorescence and absorbance spectra are observed also upon injection of the anti-DEAC antibody, attributed to the specific binding of the antibody to DEAC moieties. Importantly, protein binding occurs exclusively when the polymer is in the well hydrated state below the cloud point, enabling a temperature control on the molecular recognition event. On the other hand, heating of the polymer–antibody complexes releases a fraction of the bound antibody. In the presence of the DEAC-functionalized monomer in this mixture, the released antibody competitively binds to the monomer and the antibody-free chains of the polymer undergo a more effective collapse and inter-aggregation. In contrast, the emission properties of the OEGMA-based analogous copolymer are rather insensitive to the thermally induced phase transition or to antibody binding. These opposite behaviours underline the need for a carefully tailored molecular design of responsive polymers aimed at specific applications, such as biosensing.
The folding of single-stranded telomeric DNA into guanine (G) quadruplexes is a conformational change that plays a major role in sensing and drug targeting. The telomeric DNA can be placed on DNA origami nanostructures to make the folding process extremely selective for K+ ions even in the presence of high Na+ concentrations. Here, we demonstrate that the K+-selective G-quadruplex formation is reversible when using a cryptand to remove K+ from the G-quadruplex. We present a full characterization of the reversible switching between single-stranded telomeric DNA and G-quadruplex structures using Förster resonance energy transfer (FRET) between the dyes fluorescein (FAM) and cyanine3 (Cy3). When attached to the DNA origami platform, the G-quadruplex switch can be incorporated into more complex photonic networks, which is demonstrated for a three-color and a four-color FRET cascade from FAM over Cy3 and Cy5 to IRDye700 with G-quadruplex-Cy3 acting as a switchable transmitter.
The folding of single-stranded telomeric DNA into guanine (G) quadruplexes is a conformational change that plays a major role in sensing and drug targeting. The telomeric DNA can be placed on DNA origami nanostructures to make the folding process extremely selective for K+ ions even in the presence of high Na+ concentrations. Here, we demonstrate that the K+-selective G-quadruplex formation is reversible when using a cryptand to remove K+ from the G-quadruplex. We present a full characterization of the reversible switching between single-stranded telomeric DNA and G-quadruplex structures using Förster resonance energy transfer (FRET) between the dyes fluorescein (FAM) and cyanine3 (Cy3). When attached to the DNA origami platform, the G-quadruplex switch can be incorporated into more complex photonic networks, which is demonstrated for a three-color and a four-color FRET cascade from FAM over Cy3 and Cy5 to IRDye700 with G-quadruplex-Cy3 acting as a switchable transmitter.
Objective:
Rejection sensitivity and justice sensitivity are personality traits that are characterized by frequent perceptions and intense adverse responses to negative social cues. Whereas there is good evidence for associations between rejection sensitivity, justice sensitivity, and internalizing problems, no longitudinal studies have investigated their association with eating disorder (ED) pathology so far. Thus, the present study examined longitudinal relations between rejection sensitivity, justice sensitivity, and ED pathology.
Method:
Participants (N = 769) reported on their rejection sensitivity, justice sensitivity, and ED pathology at 9-19 (T1), 11-21 (T2), and 14-22 years of age (T3).
Results:
Latent cross-lagged models showed longitudinal associations between ED pathology and anxious rejection sensitivity, observer and victim justice sensitivity. T1 and T2 ED pathology predicted higher T2 and T3 anxious rejection sensitivity, respectively. In turn, T2 anxious rejection sensitivity predicted more T3 ED pathology. T1 observer justice sensitivity predicted more T2 ED pathology, which predicted higher T3 observer justice sensitivity. Furthermore, T1 ED pathology predicted higher T2 victim justice sensitivity.
Discussion:
Rejection sensitivity-particularly anxious rejection sensitivity-and justice sensitivity may be involved in the maintenance or worsening of ED pathology and should be considered by future research and in prevention and treatment of ED pathology. Also, mental health problems may increase rejection sensitivity and justice sensitivity traits in the long term.
Meaning and alternatives
(2022)
Alternatives and competition in language are pervasive at all levels of linguistic analysis. More specifically, alternatives have been argued to play a prominent role in an ever-growing class of phenomena in the investigation of natural language meaning. In this article, we focus on scalar implicatures, as they are arguably the most paradigmatic case of an alternative-based phenomenon. We first review the main challenge for theories of alternatives, the so-called symmetry problem, and we briefly discuss how it has shaped the different approaches to alternatives. We then turn to two more recent challenges concerning scalar diversity and the inferences of sentences with multiple scalars. Finally, we describe several related alternative-based phenomena and recent conceptual approaches to alternatives. As we discuss, while important progress has been made, much more work is needed both on the theoretical side and on understanding the empirical landscape better.
Although morphosyntax has been identified as a major source of difficulty for adult (nonnative) language learners, most previous studies have examined a limited set of largely affix-based phenomena. Little is known about word-based morphosyntax in late bilinguals and of how morphosyntax is represented and processed in a nonnative speaker's lexicon. To address these questions, we report results from two behavioral experiments investigating stem variants of strong verbs in German (which encode features such as tense, person, and number) in groups of advanced adult learners as well as native speakers of German. Although the late bilinguals were highly proficient in German, the results of a lexical priming experiment revealed clear native-nonnative differences. We argue that lexical representation and processing relies less on morphosyntactic information in a nonnative than in a native language.
Although morphosyntax has been identified as a major source of difficulty for adult (nonnative) language learners, most previous studies have examined a limited set of largely affix-based phenomena. Little is known about word-based morphosyntax in late bilinguals and of how morphosyntax is represented and processed in a nonnative speaker's lexicon. To address these questions, we report results from two behavioral experiments investigating stem variants of strong verbs in German (which encode features such as tense, person, and number) in groups of advanced adult learners as well as native speakers of German. Although the late bilinguals were highly proficient in German, the results of a lexical priming experiment revealed clear native-nonnative differences. We argue that lexical representation and processing relies less on morphosyntactic information in a nonnative than in a native language.
This study examines the discourse basis for referent accessibility and its relation to the choice of referring expressions by children with Autism Spectrum Disorder (ASD) and typically developing children. The aim is to delineate how the linguistic and extra-linguistic context affects referent accessibility to the speaker. The study also examines the degree to which accessibility effects are modulated by cognitive factors such as working memory capacity. In the study, the contrast levels between the referent and a competitor (one contrast/two contrasts) and the syntactic prominence of the referent (subject/object position in the preceding question) were manipulated in an elicited production task. The results provide evidence that the referring expressions of children with ASD correlate with the discourse status of referents to a similar extent as in typically developing controls. All children were more likely to refer with lexical NPs to referents that contrasted on two levels with a highly prominent competitor, compared to referents that contrasted on one level. They were also more likely to produce pronouns for referents previously mentioned in the subject than the object position. The effect of both discourse factors was modulated by the age and working memory capacity of the children with and without ASD. Accordingly, the study suggests that children with ASD do not generally differ from children with typical development in their referential choices when the discourse status of a referent allows them to model the referent's accessibility from their own discourse perspective in a way that is modulated by working memory capacity.
The purpose of this study was to examine the test-retest reliability, and convergent and discriminative validity of a new taekwondo-specific change-of-direction (COD) speed test with striking techniques (TST) in elite taekwondo athletes. Twenty (10 males and 10 females) elite (athletes who compete at national level) and top-elite (athletes who compete at national and international level) taekwondo athletes with an average training background of 8.9 ± 1.3 years of systematic taekwondo training participated in this study. During the two-week test-retest period, various generic performance tests measuring COD speed, balance, speed, and jump performance were carried out during the first week and as a retest during the second week. Three TST trials were conducted with each athlete and the best trial was used for further analyses. The relevant performance measure derived from the TST was the time with striking penalty (TST-TSP). TST-TSP performances amounted to 10.57 ± 1.08 s for males and 11.74 ± 1.34 s for females. The reliability analysis of the TST performance was conducted after logarithmic transformation, in order to address the problem of heteroscedasticity. In both groups, the TST demonstrated a high relative test-retest reliability (intraclass correlation coefficients and 90% compatibility limits were 0.80 and 0.47 to 0.93, respectively). For absolute reliability, the TST’s typical error of measurement (TEM), 90% compatibility limits, and magnitudes were 4.6%, 3.4 to 7.7, for males, and 5.4%, 3.9 to 9.0, for females. The homogeneous sample of taekwondo athletes meant that the TST’s TEM exceeded the usual smallest important change (SIC) with 0.2 effect size in the two groups. The new test showed mostly very large correlations with linear sprint speed (r = 0.71 to 0.85) and dynamic balance (r = −0.71 and −0.74), large correlations with COD speed (r = 0.57 to 0.60) and vertical jump performance (r = −0.50 to −0.65), and moderate correlations with horizontal jump performance (r = −0.34 to −0.45) and static balance (r = −0.39 to −0.44). Top-elite athletes showed better TST performances than elite counterparts. Receiver operating characteristic analysis indicated that the TST effectively discriminated between top-elite and elite taekwondo athletes. In conclusion, the TST is a valid, and sensitive test to evaluate the COD speed with taekwondo specific skills, and reliable when considering ICC and TEM. Although the usefulness of the TST is questioned to detect small performance changes in the present population, the TST can detect moderate changes in taekwondo-specific COD speed.
The purpose of this study was to examine the test-retest reliability, and convergent and discriminative validity of a new taekwondo-specific change-of-direction (COD) speed test with striking techniques (TST) in elite taekwondo athletes. Twenty (10 males and 10 females) elite (athletes who compete at national level) and top-elite (athletes who compete at national and international level) taekwondo athletes with an average training background of 8.9 ± 1.3 years of systematic taekwondo training participated in this study. During the two-week test-retest period, various generic performance tests measuring COD speed, balance, speed, and jump performance were carried out during the first week and as a retest during the second week. Three TST trials were conducted with each athlete and the best trial was used for further analyses. The relevant performance measure derived from the TST was the time with striking penalty (TST-TSP). TST-TSP performances amounted to 10.57 ± 1.08 s for males and 11.74 ± 1.34 s for females. The reliability analysis of the TST performance was conducted after logarithmic transformation, in order to address the problem of heteroscedasticity. In both groups, the TST demonstrated a high relative test-retest reliability (intraclass correlation coefficients and 90% compatibility limits were 0.80 and 0.47 to 0.93, respectively). For absolute reliability, the TST’s typical error of measurement (TEM), 90% compatibility limits, and magnitudes were 4.6%, 3.4 to 7.7, for males, and 5.4%, 3.9 to 9.0, for females. The homogeneous sample of taekwondo athletes meant that the TST’s TEM exceeded the usual smallest important change (SIC) with 0.2 effect size in the two groups. The new test showed mostly very large correlations with linear sprint speed (r = 0.71 to 0.85) and dynamic balance (r = −0.71 and −0.74), large correlations with COD speed (r = 0.57 to 0.60) and vertical jump performance (r = −0.50 to −0.65), and moderate correlations with horizontal jump performance (r = −0.34 to −0.45) and static balance (r = −0.39 to −0.44). Top-elite athletes showed better TST performances than elite counterparts. Receiver operating characteristic analysis indicated that the TST effectively discriminated between top-elite and elite taekwondo athletes. In conclusion, the TST is a valid, and sensitive test to evaluate the COD speed with taekwondo specific skills, and reliable when considering ICC and TEM. Although the usefulness of the TST is questioned to detect small performance changes in the present population, the TST can detect moderate changes in taekwondo-specific COD speed.