Marked pointing facilitates learning part names: A test of lexical constraint versus social pragmatic accounts of word learning.

The empirical study of word learning is driven by a theoretical debate between lexical constraint and social-pragmatic accounts; it has still not been determined which of these two best explains the evidence. We investigated whether the markedness of a pointing accompanying a verbal reference could help to learn a part name. Participants were 35 two-and-a-half-year-olds, 42 four-and-a-half-year-olds, and 38 undergraduate university students in Japan. The experimenter pointed to a novel part (embedded in a novel whole object) with either "marked" pointing, which was touching the part with a small circular motion, or with usual pointing. Touch accompanied by circular motion reliably elicited learning of part names in all age groups. Usual distal pointing without motion reliably elicited learning of whole object names. The pattern of findings rejects a whole-object constraint in early word learning and demonstrates that marked pointing can promote learning novel part names, supporting a social-pragmatic account.

Time-lapse observations to analyze the effects of assisted hatching.

PURPOSE: Assisted hatching (AH) is an artificial disruption of the zona pellucida with the aim of facilitating embryo implantation. We used time-lapse observations of mouse embryos to examine the effect of AH in mouse blastocysts. METHODS: AH techniques were performed with acid Tyrode's solution. We compared the rates of blastocyst formation and blastocyst attachment to Ishikawa cells between the control (n = 28) and the AH group (n = 24). To analyze the effects of AH, 8-cell mice embryos were cultured under time-lapse observations (every 15 min). The time required for hatching, the hatching rates, the frequency of contraction, and the contraction rates in the blastocysts were analyzed. RESULTS: There were no significant differences between the two groups in hatching rate or attachment rate. The times required for hatching were 286 ± 22 min in the AH group and 990 ± 437 min in the control group (P = 0.018). The contraction frequencies in blastocysts were 3.5 ± 0.7 times in the AH group and 7.5 ± 2.5 times in the control group (P = 0.020). CONCLUSIONS: From the time-lapse observations we found that the time required for hatching and the frequency of contraction in blastocysts were both reduced by AH, although blastocyst formation and attachment were not affected.

Regioselective intramolecular [3+2] annulation of allene-nitrones.

The regioselective intramolecular 1,3-dipolar cycloaddition of the phenylsulfonylallene-nitrone derivatives has been developed. This reaction showed that the distal double bond of the allene exclusively reacted with the nitrone group to produce the bicyclic isoxazolidine derivatives regardless of the substitution pattern on the allenyl moiety.

Ostensive gaze shifting changes referential intention in word meanings: An examination of children's learning of part names.

Learning part names, such as hands of a clock, can be a challenge for children because of the whole object assumption; that is, a child will assume that a given label refers to the whole object (e.g., a clock) rather than the object part (e.g., hands of a clock). We examined the effect of gaze shifting and deliberate pointing on learning part names. The experiment consisted of 2 conditions: (a) no-shifting and (b) shifting-to-object. No-shifting was when the experimenter continuously looked at the participant's face after establishing mutual gaze even while pointing at an object part to teach the part name. The shifting-to-object condition was the same as the no-shifting condition, except for the experimenter's gaze shifting to the object when teaching part names. The results showed that 4-and-a-half-year-olds and adults correctly inferred a part name only during gaze shifting. Two-and-a-half-year-olds were not yet sensitive to this ostensive flow. Especially while learning part names, a continuous gaze at the face may violate the quantity maxim-that is, the criterion that the speaker must provide the appropriate amount of information-in Grice's cooperative principle. To utilize ostensive signals in learning part names, children need to notice the combination of gaze direction and ostensive signals, such as a pointing gesture. In 4-and-a-half-year-olds, the use of social-pragmatic information is more advanced, allowing them to understand an adult's pointing gesture when gaze shifting occurs. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Evaluation of the safety of time-lapse observations for human embryos.

PURPOSE: To assess the effects of light from an integrated optical microscope and evaluate the safety of time-lapse observations using a built-in microscope incubator. METHODS: We prospectively compared the fertilization rate and embryonic morphology after intracytoplasmic sperm injection between embryos cultured with time-lapse observations every 15 min in an incubator with an integrated optical microscope and embryos with intermittent observations (once a day) in conventional incubators. RESULTS: No significant differences were observed in the fertilization rate (57.5% vs. 57.5%) or the rate of excellent-good cleavage embryos (36.0% vs. 36.0%). CONCLUSIONS: These results suggest that time-lapse observations using an incubator with an integrated optical microscope may therefore be safely utilized in clinical practice.

[Simple and rapid microbiological method for determination of residual antibacterials in meat].

A simple and rapid screening method using bioassay for the simultaneous analysis of antibacterials (penicillins, cephalosporins, macrolides, tetracyclines, quinolones, etc.) in meat has been developed. A 5 g sample was homogenized with 5 mL of methanol, and the homogenate was centrifuged for 10 min with 3,000 rpm. The pulp disk method with Bacillus subtilis BGA (Antibiotic Medium 5 (pH 8) and 8 (pH 6)), Micrococcus luteus ATCC 9341 and Geobacillus stearothermophilus as test organisms was employed for the assay of the antibacterials. Typical antibacterials (penicillin G, ampicillin, cefapirin, cefalexin, erythromycin, spiramycin, oxytetracycline, chlortetracycline, streptomycin, dihydrostreptomycin, enrofloxacin and oxolinic acid) were detected at levels of ca. 0.005-2.5 microg/g in meat. Therefore, we recommend this proposed screening method for routine analysis of residual antibacterials in livestock products.

Composition and structure of the centromeric region of rice chromosome 8.

Understanding the organization of eukaryotic centromeres has both fundamental and applied importance because of their roles in chromosome segregation, karyotypic stability, and artificial chromosome-based cloning and expression vectors. Using clone-by-clone sequencing methodology, we obtained the complete genomic sequence of the centromeric region of rice (Oryza sativa) chromosome 8. Analysis of 1.97 Mb of contiguous nucleotide sequence revealed three large clusters of CentO satellite repeats (68.5 kb of 155-bp repeats) and >220 transposable element (TE)-related sequences; together, these account for approximately 60% of this centromeric region. The 155-bp repeats were tandemly arrayed head to tail within the clusters, which had different orientations and were interrupted by TE-related sequences. The individual 155-bp CentO satellite repeats showed frequent transitions and transversions at eight nucleotide positions. The 40 TE elements with highly conserved sequences were mostly gypsy-type retrotransposons. Furthermore, 48 genes, showing high BLAST homology to known proteins or to rice full-length cDNAs, were predicted within the region; some were close to the CentO clusters. We then performed a genome-wide survey of the sequences and organization of CentO and RIRE7 families. Our study provides the complete sequence of a centromeric region from either plants or animals and likely will provide insight into the evolutionary and functional analysis of plant centromeres.

Physical maps and recombination frequency of six rice chromosomes.

We constructed physical maps of rice chromosomes 1, 2, and 6-9 with P1-derived artificial chromosome (PAC) and bacterial artificial chromosome (BAC) clones. These maps, with only 20 gaps, cover more than 97% of the predicted length of the six chromosomes. We submitted a total of 193 Mbp of non-overlapping sequences to public databases. We analyzed the DNA sequences of 1316 genetic markers and six centromere-specific repeats to facilitate characterization of chromosomal recombination frequency and of the genomic composition and structure of the centromeric regions. We found marked changes in the relative recombination rate along the length of each chromosome. Chromosomal recombination at the centromere core and surrounding regions on the six chromosomes was completely suppressed. These regions have a total physical length of about 23 Mbp, corresponding to 11.4% of the entire size of the six chromosomes. Chromosome 6 has the longest quiescent region, with about 5.6 Mbp, followed by chromosome 8, with quiescent region about half this size. Repetitive sequences accounted for at least 40% of the total genomic sequence on the partly sequenced centromeric region of chromosome 1. Rice CentO satellite DNA is arrayed in clusters and is closely associated with the presence of Centromeric Retrotransposon of Rice (CRR)- and RIce RetroElement 7 (RIRE7)-like retroelement sequences. We also detected relatively small coldspot regions outside the centromeric region; their repetitive content and gene density were similar to those of regions with normal recombination rates. Sequence analysis of these regions suggests that either the amount or the organization patterns of repetitive sequences may play a role in the inactivation of recombination.