Two studies are reported in which the effects of supervisor observations of teachers' performance rate and accuracy on both teachers' and severely handicapped students' behaviors were compared with baseline supervisor observations that did not specify rate and accuracy feedback. The latter observation procedure (nonspecific feedback) was more typical of the existing practices of school supervisors. The dependent variables for the teachers were rate and accuracy of teacher behaviors to student responses in individualized instructional settings involving discrete trials or task-analysis steps. The dependent variables for students were the rates of correct and incorrect responding to teacher presentations during the supervisor observation periods. Both studies used a multiple baseline design. The results of Study 1 showed that there were educationally significant changes in teacher and, in turn, student performance as a result of the use of the rate and accuracy procedure. The results of Study 2 replicated those of Study 1 while correcting limitations of Study 1. This latter study also demonstrated that the observation effects of the procedure generalized to teacher performance throughout the day. The results are discussed in terms of the efficiency and cost effectiveness of the procedure to train, monitor, and reinforce teacher effectiveness.

Adolescent↗

PubMed1990

Cell patterning in the Drosophila segment: spatial regulation of the segment polarity gene patched.

Intrasegmental patterning in the Drosophila embryo requires the activity of the segment polarity genes. The acquisition of positional information by cells during embryogenesis is reflected in the dynamic patterns of expression of several of these genes. In the case of patched, early ubiquitous expression is followed by its repression in the anterior portion of each parasegment; subsequently each broad band of expression splits into two narrow stripes. In this study we analyse the contribution of other segment polarity gene functions to the evolution of this pattern; we find that the first step in patched regulation is under the control of engrailed whereas the second requires the activity of both cubitus interruptusD and patched itself. Furthermore, the products of engrailed, wingless and hedgehog are essential for maintaining the normal pattern of expression of patched.

Animals↗

PubMed1988

Region-specific alleles of the Drosophila segmentation gene hairy.

An essential step in the Drosophila segmentation mechanism is the expression of the pair-rule gene hairy in a periodic pattern in the blastoderm. In this paper we describe four regulatory hairy mutations. Using in situ hybridization, we show that these mutations cause alterations in the normal pattern of hairy expression. The new patterns are partial versions of the wild-type pattern and indicate that there are regulatory sequences associated with hairy that respond to distinct cues in different parts of the blastoderm. This suggests that a major function of hairy is to decode a prepattern consisting of complex cues (probably generated by the coordinate and gap classes of segmentation genes) into a simple periodic pattern. We have located the mutations on the DNA map of the hairy gene. They identify a 5' region of approximately less than 20 kb necessary for this decoding function.

Alleles↗

PubMed1988

Tissue- and stage-specific control of homeotic and segmentation gene expression in Drosophila embryos by the polyhomeotic gene.

The distributions of the products of the homeotic genes Sex combs reduced (Scr) and Ultrabithorax (Ubx) and of the segmentation genes, fushi tarazu (ftz), even skipped (eve) and engrailed (en) have been monitored in polyhomeotic (ph) mutant embryos. None of the genes monitored show abnormal expression at the blastoderm stage in the absence of zygotic ph expression. Both Scr and Ubx are ectopically expressed in the epidermis of ph embryos, confirming the earlier proposal, based on genetic analysis, that ph+ acts as a negative regulator of Antennapedia (ANT-C) and bithorax (BX-C) complex genes. At the shortened germ band stage, en is also ectopically expressed, mainly in the anterior region of each segment. In contrast to these effects in the epidermis, the expression of en, Ubx, Scr and ftz is largely or completely suppressed in the central nervous system, whereas eve becomes ectopically expressed in most neurones.

Animals↗

PubMed1986

Isolation, structure, and expression of even-skipped: a second pair-rule gene of Drosophila containing a homeo box.

We report the isolation, sequence, and transcriptional behavior of the Drosophila even-skipped (eve) gene, a member of the pair-rule class of segmentation genes. We show that the eve gene contains a homeo box and hence is related structurally to the pair-rule gene fushi tarazu and to homeotic selector genes. However, the eve homeo box differs significantly from those previously described and encodes a putative DNA recognition helix that would probably recognize different sequences. The eve gene resembles other pair-rule genes in showing a transient seven stripe zebra pattern during the blastoderm stage, but seven additional stripes arise soon thereafter. Together, these 14 stripes are required for the activation of coincident stripes of engrailed transcripts, leading to the subdivision of the embryo into compartmental and segmental units.

Animals↗

PubMed1986

Regulatory interactions between the segmentation genes fushi tarazu, hairy, and engrailed in the Drosophila blastoderm.

The genetic loci fushi tarazu (ftz), hairy (h), and engrailed (en) must be expressed during embryogenesis for the correct segmental organization of the Drosophila embryo to be established. Transcripts from these genes accumulate in periodic patterns at the blastoderm stage of development. We demonstrate that generation of the normal pattern of ftz RNA requires the h+ function whereas formation of the h pattern does not require the ftz gene. In addition, we show that the en pattern is altered in both h and ftz mutant embryos. The nature of these changes and the cuticular phenotype of h mutant larvae suggest that both h and ftz phenotypes are a consequence of incorrect compartmentalization and that the effect of h is mediated via ftz and other genes.

Animals↗

PubMedDate not supplied

Abdominal gene organization.

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Abdomen↗