Search PubMed⌕ Search

Biomedical subjects

S A Fowler

Publications and source records attributed to S A Fowler.

At least 19 recordsLinked to original sources
PubMed1992

Isolation and characterization of the triply oxidized derivative of a cross-linked hemoglobin.

Hemoglobin A, cross-linked between Lys 99 alpha 1 and Lys 99 alpha 2, was used to obtain a partially oxidized tetramer in which only one of the four hemes remains reduced. Because of the absence of dimerization, asymmetric, partially oxidized derivatives are stable. This is evidenced by the fact that eight of the ten possible oxidation states could be resolved by analytical isoelectric focusing. A triply oxidized hemoglobin population HbXL+3 was isolated whose predominant component was (alpha + alpha +, beta + beta 0). This triferric preparation was examined as a possible model for the triliganded state of ferrous HbA. The aquomet and cyanomet derivatives were characterized by their CD spectra and their kinetic reactions with carbon monoxide. CD spectra in the region of 287 nm showed no apparent change in quaternary structure upon binding ligand to the fourth, ferrous heme. The spectra of the oxy and deoxy forms of the cyanomet and aquomet derivatives of HbXL+3 differed insignificantly and were characteristic of the normal liganded state. Upon addition of inositol hexaphosphate (IHP), both the oxy and deoxy derivatives of the high-spin triaquomet species converted to the native deoxy conformation. In contrast, IHP had no such effect on the conformation of the low-spin cyanomet derivatives of HbXL+3. The kinetics of CO combination as measured by stopped-flow and flash photolysis techniques present a more complex picture. In the presence of IHP the triaquomet derivative does bind CO with rate constants indicative of the T state whether these are measured by the stopped-flow technique or by flash photolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗
PubMed1992

An analysis of the effects of multiple setting events on the social behavior of preschool children with special needs.

We examined the effects of four combinations of setting events on the social interactions of 7 preschool children with social delays. In Study 1, the status of the teacher, activity materials, and peer varied across conditions. In Study 2, the status of the teacher and materials varied across conditions. Within the combinations of setting events, we also examined teacher behavior. Teacher presence and absence was varied in both studies. The type and rate of teacher prompting were varied in Study 2. The four combinations of setting events produced different rates of social behavior by the children with social delays. The optimal combination of setting events for promoting peer interaction and reducing teacher-child interaction included teacher absence from the activity, a limited number and form of materials, and children paired with a socially skilled partner.

Aggression↗
PubMed1992

Generalization and maintenance of preschool children's social skills: a critical review and analysis.

This paper summarizes the results of a retrospective review of generalization in the context of social skills research with preschool children. A review of studies from 22 journals (1976 to 1990) that assessed generalization as part of social interaction research provided information concerning the prevalence of studies that have assessed generalization, common practices concerning the production and assessment of generalization, and the overall success of obtaining generalization and maintenance of social behaviors. A comparison of the most and least successful studies, with respect to generalization, revealed some differences concerning the practices employed by studies within each group. Differences differentially related to the production of generalization are discussed and recommendations are provided to guide and support future research efforts.

Behavior Therapy↗
PubMed1991

Reactivity in self-recording: obtrusiveness of recording procedure and peer comments.

Reactivity refers to behavior change that occurs during self-recording without specific programming of consequences. We analyzed the effects of obtrusiveness of recording procedure and peer comments on reactivity to self-recording. Three first-grade students in Experiment 1 completed math questions during a 5-min work period. When we gave the children recording devices and told them to try to complete more questions than the highest number they had previously completed, math performance increased, as did the number of verbalizations about it. Two children showed more reactivity when they used the more obtrusive recording device. Because the increase in math performance corresponded closely to increases in peer comments, we manipulated peer comments directly in Experiment 2. Four second-grade students completed a math task and an alphabet task. Three of the students showed increased math performance during periods when peer comments occurred compared to periods when peer comments did not occur. Although the data from the math task suggested that peer comments can enhance reactivity, we did not observe this relationship with the alphabet task. These results suggest that the conditions necessary to produce desirable results through self-recording are complex and contextually specific.

Auditory Perception↗
PubMed1988

A comparison of two intervention roles: peer monitor and point earner.

Two fifth-grade students' high levels of off-task and disruptive behavior decreased rapidly during an intervention in which they were appointed peer monitors or point earners. The children worked in dyads in which one child served as a peer monitor and the other child earned points from his or her monitor for good behavior. Points were accumulated as part of a group contingency. We introduced the two appointments in an independent math period and alternated the appointments across days. The peer monitor and point earner roles, when alternated on an every-other-day basis, were equally effective in reducing the students' inappropriate behavior. Furthermore, their behavior during intervention fell well within the range of inappropriate behavior levels exhibited by classmates. The speed with which both students completed their math problems increased during both appointments. The accuracy of their academic work, however, varied; one student improved slightly and the other student decreased slightly in accuracy.

Achievement↗
PubMed1987

Language training for generalization.

This paper presents a classroom-based language intervention program for preschool children with language delays or deficits. A major goal of the program is to ensure that children acquire missing skills through daily speech therapy and that they actively generalize these skills from therapy times to other classroom activities. This paper presents data collected with two children during daily speech therapy sessions and daily play activities. Instances in which the children generalized new language acquired in therapy to play activities will be discussed as well as instances in which the children failed to generalize new language. In addition, the influence of peer and teacher language usage on children's language production will be discussed. Finally, recommendations to enhance generalization of language skills within and across school settings will be presented.

Child↗
PubMed1986

Binding of iron by factor IX. Possible role for beta-hydroxyaspartic acid.

In concentrations exceeding 1 mg/ml, bovine factor IX exhibits a pink color that arises from a broad absorption band with a lambda max = 500 nm. Analysis by x-ray fluorescence reveals the presence of iron but no other transition metals in the factor IX preparation. Quantitative analysis by atomic absorption spectroscopy indicates that 1 g atom of iron is bound tightly to 1 mol of factor IX. The iron is removed slowly (t1/2 = 3 h) by EDTA. In contrast, prothrombin binds no detectable iron, and factor X binds less than 0.2 g atom/mol. alpha-Hydroxybutyrate chelates Fe3+ with sufficient stability to preclude formation of [Fe(OH)3]n. It is proposed that factor IX binds iron with physiologically significant affinity and that the beta-hydroxyaspartate residue in factor IX is a chelator for the bound metal.

Animals↗
PubMed1986

Role reversals: an analysis of therapeutic effects achieved with disruptive boys during their appointments as peer monitors.

Three 7-year-old boys with histories of negative interactions were appointed to monitor individual classmates during daily noon recess. As monitors, the boys awarded points to their classmates for playing appropriately and, on rare occasions, withdrew a point for negative interactions. The three boys immediately decreased their own rates of negative interactions during the sessions in which they were appointed as monitors. Two of the boys concomitantly increased their rates of positive interactions. Their reductions in negative interactions were not maintained during reversals and did not clearly generalize to the morning or afternoon recess periods. Subsequent appointment of the boys as peer monitors during the morning recess produced similar improvements in their behavior. Results suggest that appointment to the role of peer monitor may itself function as an intervention.

Child↗
PubMed1985

Identification of proteins in contact lens surface deposits by immunofluorescence microscopy.

Worn soft contact lenses from five asymptomatic subjects were examined by immunofluorescence microscopy for type of protein on the lens surface. Lysozyme was the predominant protein component identified by this technique. IgA was also identified in deposits on all five lenses, but the staining was less intense than that for lysozyme. Lactoferrin was identified on the surface of four lenses, one of which stained intensely for this protein and three less intensely. IgG was identified on two contact lenses; the staining was less intense than that for lysozyme. New, never-worn soft contact lenses did not stain for any of the proteins examined in this study. We conclude that several normal tear proteins are capable of contributing to surface deposits on soft contact lenses, and all worn soft contact lenses have protein adherent to their surface as a result of normal wear.

Adult↗
PubMed1985

The use of peer monitors to reduce negative interaction during recess.

The negative interactions of a midly retarded child, Dennis, were reduced in three daily recess periods, with the use of a point system. Adult monitors initiated the intervention in the morning recess; reductions achieved during adult monitoring were maintained in that recess during two subsequent conditions: peer monitoring and self-monitoring. Dennis' negative interactions were reduced next in the afternoon recess by peer monitors. Again, reductions were maintained during a subsequent self-monitoring condition. Finally, during the noon recess, Dennis was trained to serve as a peer monitor for Ed, a moderately retarded classmate. Dennis' rate of negative interactions quickly decreased following his appointment as a peer monitor. The results show that a point system, originally designed for adult monitoring, can be adapted without loss of program effectiveness for peer monitoring or self-monitoring. The results also suggest that classmates who serve as peer monitors may benefit significantly from their role. The conditions under which these therapeutic effects occur and the role that treatment order effects may play in this process require further investigation.

Aggression↗
PubMed1985

Training prosocial behaviors to young children: an analysis of reciprocity with untrained peers.

We examined the effects of a social skills training package on the play behaviors of three young girls. Two children were taught to invite their peers to play and to use social amenities during their conversations with other children. A combined reversal and multiple baseline across responses design demonstrated that both children directed more social behaviors to their classroom peers after training and that these two children's play invitations were maintained in the later absence of experimental contingencies. In addition, both target children received a greater number of play invitations from their peers during the free play periods. In contrast, a third child's play invitations were not reciprocated by peers; her invitations subsequently decreased in rate after training was discontinued. An interdependent group contingency produced a reciprocal exchange of invitations between this child and her classroom peers. A reversal design demonstrated partial maintenance of subject-peer exchanges after the group intervention was discontinued. The results obtained with the three target children suggest that peer reciprocity may facilitate the maintenance of children's play invitations over time.

Behavior Therapy↗
PubMed1979

Attachment of bacteria to soft contact lenses.

A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers and eight patients with contact lens-associated giant papillary conjunctivitis were examined by scanning electron microscopy. Structures that resembled bacteria were present on the anterior surface of seven lenses. All lenses showed a coating of granular mucus-like deposits. Some bacteria were seen scattered randomly over the surface, with no apparent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes, the distal ends of which were unattached. These attached bacteria were cylindrical in shape. Several bacteria showed a constriction centrally. Some bacteria were covered by the surface coating, while others, which were round to ovoid in shape, appeared partially embedded in the coating itself. Aggregations of bacteria were seen around clumps of mucus-like debris.

Bacteria↗
PubMed1979

Soft contact lenses from patients with giant papillary conjunctivitis.

We used scanning electron microscopy to study the surfaces of five coated soft contact lenses from subjects with giant papillary conjunctivitis. Findings were compared to the surfaces of five coated lenses from normal, asymptomatic wearers and five new, nerver-worn lenses. Lenses were from various manufacturers. All worn contact lenses differed strikingly from new, never-worn lenses. The anterior surface of worn lenses was covered with apparently adherent deposits. In only a few areas was the surface similar to new, never-worn lenses. Thick coatings on lenses from patients with giant papillary conjunctivitis and asymptomatic wearers were similar. High magnification of the coatings revealed a trabeculated morphology. Also seen was debris that resembled mucus-like material in both strand and particulate forms. On some lenses bacterial-shaped structures were scattered randomly over the surface. Smooth structures resembling cells were also seen. The posterior lens surface of all worn lenses was smoother than the anterior lens surface. The findings support our idea that the capacity to develop giant papillary conjunctivitis is influenced by individual differences more than by differences in lens deposits.

Adult↗
PubMed1978

Calcium and 25-hydroxyvitamin D3 binding proteins in human placenta.

The placental translocation of calcium is a well-known process, but the underlying mechanisms remain unknown. Placental cytoplasmic proteins capable of binding calcium and the active metabolites of vitamin D3 were sought in these studies. Cytosol from full-term human placenta was prepared by ultracentrifugation of homogenates and tested for binding. Partial purification by column chromatography revealed the presence of two discrete proteins which bound specifically 45Ca and 3H-25-hydroxyvitamin D3 and having approximate molecular weights of 12,000 and 67,000, respectively. These placental proteins may be intermediaries in the process of placental calcium translocation.

Calcium↗
PubMed1978

Training preschool children to recruit natural communities of reinforcement.

Four normal and four deviant children aged four-to-six years were taught to judge the quality of their academic work in a preschool classroom, and to prompt or cue their teachers to comment about the quality of that work. When these skills did not generalize spontaneously to other teachers in concurrent natural situations, generalized responding was taught by the experimenter, in multiple-baseline design across subjects. This generalization programming enabled the children to contact a sometimes dormant, but readily available natural community of teacher praise and reinforcement, i.e., to recruit an increase in cued praise and schedules of praise for their good work. These behaviors may be important to young children who find themselves bereft of attention in classrooms.

Child↗
PubMed1976

Color-matching technique to train children in the correct use of stairs.

Color cues were used to train four severely retarded children and two learning disabled children to move in a left foot-right foot alteration pattern when using stairs. The occurrence of left-right alterations and marking time behavior was recorded throughout baseline and training conditions. The color-cue procedure effectively produced a consistent pattern of alteration of four of the children and eliminated marking time in three of the children. Physical prompts were used to train alteration in two children for whom color-cue training was not sufficient. At the termination of training, observations of the children's performances in new settings and to new adults were conducted. Results indicated that the children continued to alternate correctly. In addition, follow-up investigations conducted between two weeks to 16 months after training indicated that the children were maintaining the stair alteration pattern. Future research should determine whether a visual-cue procedure could be used in training other forms of locomotion or motor behavior.

Adolescent↗
PubMedDate not supplied

Perspectives on the transition from preschool to kindergarten for children with disabilities and their families.

This article addresses the transition of young children from preschool programs that provide special education services to kindergarten or alternative elementary school placements. The roles of the child, family, and service providers in transition preparation, planning, implementation, and evaluation are described. Successful transitions include assessments of children's skills in meeting the demands of kindergarten programs, teaching these skills to children, and actively encouraging parent participation in plans and programs. Barriers to successful transitions include lack of time and funding to coordinate both parent activities and between-school arrangements. A critical area for future research is the long-term evaluation of the procedures described as "best practice," as well as the definition of what constitutes a successful transition.

Child, Preschool↗