Polynuclear Ni(II) Complexes with Schiff Bases as Bridging Ligands: A Molecular Approach to Nanoscience

The initial employment of N-salicylidene-2-amino-5-chlorobenzoic acid (sacbH2) as bridging/chelating ligand in metal cluster chemistry has provided access to five new polynuclear NiII complexes with large nuclearities, unprecedented metal core topologies, and interesting magnetic properties. The obtained results are presented in two projects. The first project includes the investigation of the general Ni2+/RCO2-/sacbH2 reaction system (where R- = CH3-, But-, ButCH2-) in which the nature of the carboxylic acid was found to be of crucial importance, affecting enormously the nuclearity of the resulting complexes. The second project deals with the study of the general Ni2+/X-/sacbH2 reaction system (where X- = inorganic anions) under basic conditions, yielding new cluster compounds with molecular chain-like structures and ferromagnetic exchange interactions between the metal centers

The Effect of Focus on Creaky Phonation in Mandarin Chinese Tones

Previous studies of the prosodic realization of focus in Mandarin Chinese show an expansion of the pitch range of lexical tones. It is less clear, however, whether focus affects the Creaky Phonation (CP) that often co-occurs with the Dipping third tone (T3), and to some extent, also with the Falling fourth tone (T4). This study investigates the effect of focus on the acoustic properties of the four Mandarin tones, and while it confirms the expansion of the pitch range under focus, it does not find that focus affects CP in T3; it only finds an effect of focus on CP in T4. Both the F0 and CP patterns are also considered in relation to the Functional Load Hypothesis, specifically, the relationship between the contrastive properties of a language and the manifestation of prominence

Acoustic properties of word and phrasal prominence in Uzbek

Based on a large-scale corpus of experimental data produced by 8 native speakers of Tashkent Uzbek, we assess the presence of canonical word-final stress in real words spoken in three dialogue types: without focus, with contrastive focus, and with new information focus on the target. The first context provides baseline information regarding the manifestation of stress, in the absence of additional focus properties. By comparing the latter two contexts with the former, we are also able to assess the acoustic manifestation of the two types of focus. The most noteworthy properties of the final syllable are its relatively long duration and sharp falling contour, potentially serving as the cues to lexical stress, and enhanced by both types of focus. Due to the word-final position of stress, however, the patterns we observe could also be consistent with boundary properties, a possibility we consider as well. In addition, we briefly compare the prosodic patterns we observe in Uzbek with similarly collected data in Turkish. We find that the prominence patterns in Uzbek, while not particularly strong, are nevertheless stronger than those in Turkish, and also exhibit crucial differences. Implications for Turkic prosody more generally are also suggested

Perceptual Confusion of Mandarin Tone 3 and Tone 4

In connected speech, the acoustic properties of Mandarin tones undergo modifications not observed in isolation. The current study investigated the perceptual distinction between Mandarin tones in connected speech, focusing on Tone 3 and Tone 4, which have been reported to share a similar initial falling contour. The current study also tested whether syllables produced with focus and / or in certain syllable positions affect the tonal perception. In a forced choice perception task, participants heard syllables extracted from three syllable words previously recorded in short dialogues, and were instructed to select one of four characters representing corresponding monosyllabic words differing only in tone. The accuracy results showed that Tone 4 was much more successfully identified than Tone 3. Nonetheless, after using a d-prime analysis to control for an observed T4 response bias, we found the same level of perceptibility of T3 and T4. Furthermore, the two tones were better perceived when a tone was produced in a focus context or at the edge of a word, confirming the effect of prosodic structure on tonal perception

A one-year classroom-randomized trial of mental abacus instruction for first- and second-grade students

Mental Abacus (MA) is a popular arithmetic technique in which students learn to solve math problems by visualizing a physical abacus structure. Prior studies conducted in Asia have found that MA can lead to exceptional mathematics achievement in highly motivated individuals, and that extensive training over multiple years can also benefit students in standard classroom settings. Here we explored the benefits of shorter-term MA training to typical students in a US school. Specifically, we tested whether MA (1) improves arithmetic performance relative to a standard math curriculum, and (2) leads to changes in spatial working memory, as claimed by several recent reports. To address these questions, we conducted a one-year, classroom-randomized trial of MA instruction. We found that first-graders students struggled to achieve abacus expertise over the course of the year, while second-graders were more successful. Neither age group showed a significant advantage in cognitive abilities or mathematical computation relative to controls, although older children showed some hints of an advantage in learning place-value concepts. Overall, our results suggest caution in the adoption of MA as a short-term educational intervention

{Ni4} Cubanes from enantiomerically pure 2-(1-hydroxyethyl)pyridine ligands: supramolecular chirality

Homometallic {NiII4} cubane-like clusters with a rare chiral core have been prepared via the employment of enantiomerically pure 2-(1-hydroxyethyl)pyridine (Hmpm). Comparison with the achiral cubanes derived from the related 2-pyridinemethanol (Hpym) ligand reveals drastic structural changes as a consequence of the transfer of chirality from the ligands to the whole structure. Their magnetic properties have been related to the structural features of their cubane-type cores

Multidimensional Signals and Analytic Flexibility: Estimating Degrees of Freedom in Human-Speech Analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis that can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling but also from decisions regarding the quantification of the measured behavior. In this study, we gave the same speech-production data set to 46 teams of researchers and asked them to answer the same research question, resulting in substantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further found little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise, or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system, and calibrate their (un)certainty in their conclusions

Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions