Biomedical subjects
A Swain
Publications and source records attributed to A Swain.
Effects of goal-setting interventions on selected basketball skills: a single-subject design.
The purpose of this investigation was to examine the effects of a goal-setting intervention program on selected components of basketball performance over the course of a competitive season. A multiple-baseline, single-subject design was used with baseline observations on various performance components (e.g., turnovers, rebounds), collected for four elite college basketball players during their first eight games of the season. At the midseason break, these players selected one aspect of their play that they felt would benefit from improvement. A goal-setting program was designed based on the goal attainment scaling procedure recommended by Smith (1988), whereby subjects generated numerical targets for their chosen components. Performance components were then assessed for the next eight games as they had been in the preintervention phase. Following the intervention, 3 of the 4 subjects showed consistent improvements in their targeted areas of performance. Also, there were no outcome changes in the performance components that weren't targeted by the subjects. The findings suggest that future studies may benefit from achieving greater ecological validity and utilizing alternative designs to the traditional nomothetic approaches which may tend to mask positive intervention effects on certain individuals.
Circular transcripts of the testis-determining gene Sry in adult mouse testis.
Sry is expressed at higher levels in the adult testis, where no function has been determined, than in the genital ridge, its critical site of action. cDNA and 5' RACE clones isolated from testis or from Sry-transfected cell lines have an unusual structure, with 3' sequences located in a 5' position. RNAase protection assays and reverse transcription polymerase chain reactions confirmed that these unusual RNA molecules represent the most abundant transcript in testis. Furthermore, oligonucleotide hybridization and RNAase H digestion proved that these Sry RNA molecules are circular. Similar transcripts were detected in the testes of mice with Mus musculus musculus, Mus musculus domesticus, and Mus spretus Sry genes. The circular RNA is found in the cytoplasm but is not substantially bound to polysomes. We suggest that the circles arise from normal splicing processes as a consequence of the unusual genomic structure surrounding the Sry locus in the mouse.
Intensity and direction dimensions of competitive state anxiety and relationships with performance.
This study examined relationships between intensity and direction dimensions of competitive state anxiety, and also relationships with beam performance in a sample of female gymnasts. The 48 gymnasts, whose ages ranged from 14 to 16 years, competed in a beam competition and were divided, via the median split technique, into poor performance and good performance groups. All the subjects completed a modified version of the Competitive State Anxiety Inventory-2 (CSAI-2) 10 min prior to performance. This inventory included the original intensity scale plus a direction scale in which subjects rated the degree to which the experienced intensity of each symptom was either facilitative of debilitative to subsequent beam performance. Analyses of variance showed no significant group differences on any of the CSAI-2 sub-component intensity scores, or on somatic anxiety and self-confidence direction scores. However, the good performance group reported their cognitive anxiety intensity as being more facilitating and less debilitating to performance than the poor performance group. Stepwise multiple-regression analyses showed that the only significant predictor of beam performance was self-confidence intensity. These findings support the proposal that sports performers' directional perceptions of their anxiety symptoms may provide further understanding of the competitive state anxiety response, and also emphasize the importance of self-confidence in predicting performance.
Intensity and frequency dimensions of competitive state anxiety.
This study reports a preliminary investigation of intensity and frequency of symptoms of competitive state anxiety. Forty-nine track and field athletes (27 males, 22 females) responded to a modified version of the Competitive State Anxiety Inventory-2 (CSAI-2) on four occasions during the period leading up to an important competition: 2 days, 1 day, 2 h and within 30 min of competing. The questionnaire included the existing CSAI-2 (intensity) scale as well as a frequency scale for each of the 27 items of the CSAI-2. The intensity and frequency dimensions of each of the CSAI-2-sub-scales were then compared between the four conditions by means of two-way analyses of variance (gender x time-to-competition). In the case of cognitive anxiety, time-to-event effects were observed for intensity and frequency for both males and females. The intensity of the response was significantly greater at the final stage of testing than it was 2 days before competition, while the frequency of the response increased progressively throughout the experimental period. This dissociative patterning for the cognitive anxiety dimensions is discussed in the light of Multidimensional Anxiety Theory predictions. For somatic anxiety, the time-to-event effects that emerged for intensity and frequency revealed that both values increased progressively as the time to compete neared, for both male and females. The results for self-confidence revealed no effects for intensity or frequency for either gender. The findings from structured follow-up interviews served to corroborate these quantitative findings by providing information that supported the conclusions drawn from the questionnaire data. In particular, the athletes reported that they experienced considerable increases in the frequency of intrusive anxiety cognitions. While these findings clearly need to be substantiated, they do provide evidence of the existence of an additional dimension of anxiety that may assist our understanding of this complex concept. The measurement of competitive state anxiety may benefit from this more detailed approach as opposed to the rather limited intensity-alone perspective.
Influence of sequences in the long terminal repeat and flanking cell DNA on polyadenylation of retroviral transcripts.
Readthrough transcripts are formed during retrovirus infection by polyadenylation of viral RNA in cellular sequences adjacent to the provirus. We have studied such transcripts in avian leukosis virus-infected cell clones containing a single provirus, either the wild type or one with an inactivating mutation in the poly(A) addition signal. All individual wild-type proviruses produced readthrough transcripts, implying that this property is not restricted to a few integration sites. The range of sizes of viral RNA in the mutant lacking a correct signal for poly(A) addition reflected both the occurrence of functional polyadenylation sites within flanking cell DNA and increased usage of cryptic sites within viral sequences.
Mechanism of transduction by retroviruses.
Retroviruses can capture cellular sequences and express them as oncogenes. Capture has been proposed to be a consequence of the inefficiency of polyadenylation of the viral genome that allows the packaging of cellular sequences flanking the integrated provirus in virions; after transfer into virions, these sequences could be incorporated into the viral genome by illegitimate recombination during reverse transcription. As a test for this hypothesis, a tissue culture system was developed that mimics the transduction process and allows the analysis and quantitation of capture events in a single step. In this model, transduction of sequences adjacent to a provirus depends on the formation of readthrough transcripts and their transmission in virions and leads to various recombinant structures whose formation is independent of sequence similarity at the crossover site. Thus, all events in the transduction process can be attributed to the action of reverse transcriptase on readthrough transcripts without involving deletions of cellular DNA.
Intensity and direction as dimensions of competitive state anxiety and relationships with competitiveness.
This study examined differences in intensity and direction of symptoms of competitive state anxiety in high and low competitive subjects from the sports of rugby union, basketball, soccer, and field hockey. The 69 men were dichotomized via a median-split into high and low competitive groups based on their scores on the Sport Orientation Questionnaire. All subjects completed a modified version of the Competitive State Anxiety Inventory-2 30 minutes prior to competition. This inventory included the original intensity scale plus a direction scale on which subjects rated the extent the experienced intensity of each symptom was either facilitative or debilitative to subsequent performance. There were no significant group differences on intensity of cognitive anxiety or of somatic anxiety or on direction of somatic anxiety; however, the highly competitive group of 34 subjects reported their anxiety as more facilitative and less debilitative than the low competitive group (n = 35). This supports the proposal that sports performers' directional perceptions of their anxiety symptoms may provide further understanding of the competitive state-anxiety response.
Biosensors: a new realism.
For many years biosensors have been hailed as the solution to many analytical problems. There is general agreement that biosensors offer the potential for easy-to-use, low-cost, rapid analysis. With such versatile, economic, reliable and cheap analytical devices at their disposal, manufacturers in industries as diverse as pharmaceuticals, food and drink, medical diagnostics and defence must surely be reaping vast profits from their biosensor-based products? In fact, biosensors have made only a very modest impact and this article attempts to present a realistic review of their current commercial potential. Consideration is given to the features and benefits of biosensors, the potential application markets, the impact of legislation, the needs of the user and the real commercial potential in the light of these factors and the existing competition.
Physical characterisation of plasmids in a morpholine-degrading mycobacterium.
The plasmid content of an environmental mycobacterium (MorG) which degrades morpholine (Mor+ phenotype) was investigated. The combination, in what appears to be a novel way, of restriction endonuclease digestion, gel electrophoresis and scanning densitometry permitted the resolution of mixed plasmid preparations into four distinct plasmids with sizes of 54 (approximately), 27.7, 22.8 and 22.6 kb. These plasmids were named pMOR1, 2, 3 and 4, respectively. The Mor+ phenotype was found to be unstable during acriflavin treatment. In four independently isolated Mor- mutants, plasmid pMOR2 was found to have acquired an insert of approximately 1.8 kb within a specific 5.9 kb BamHI fragment. It is concluded that pMOR2 is involved in the coding of the Mor+ phenotype.
ABC of major trauma. Trauma of the spine and spinal cord--II.
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ABC of major trauma. Trauma of the spine and spinal cord--I.
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Interrelationships among multidimensional competitive state anxiety components as a function of the proximity of competition.
This study examined whether the relationship between the cognitive anxiety and somatic anxiety subscales of the Competitive State Anxiety Inventory-2 changes as a function of the proximity of a competition. On five separate occasions during the period prior to an important competition 87 subjects responded to the inventory. Intercorrelations between subscale scores suggested a progressive increase in the magnitude of the relationship between cognitive and somatic anxiety as the event approached. Findings support in a sporting context the hypothesis of covariance at times of high stress.
Polyadenylation at correct sites in genome RNA is not required for retrovirus replication or genome encapsidation.
RNA transcripts polyadenylated at sites derived from flanking cellular DNA (readthrough transcripts) make up about 15% of the viral RNA in cells infected with avian leukosis virus. To test the functionality of such transcripts, a virus was created by introducing two mutations into the AAUAAA polyadenylation signal of Rous-associated virus 1, converting it to AAGGAA. The replication of this virus was not greatly affected at any level. However, less than 1% of viral transcripts produced during mutant virus replication were cleaved and polyadenylated at the correct site within viral long terminal repeat-related sequence. These results imply that readthrough transcripts, which are produced during normal viral replication, are polyadenylated and packaged into virions as normal transcripts and can serve as RNA genomes in the next round of replication. These results show that polyadenylation within virus-related sequences is not a necessary requirement for virus replication and that readthrough transcripts have the necessary properties to be intermediates in the process of transduction of cellular sequences.
Analysis of expression and thermoregulation of the Yersinia pseudotuberculosis inv gene with hybrid proteins.
A series of translational fusions between the Yersinia pseudotuberculosis inv locus and lacZ was constructed. Each Lac+ fusion strain expressed a hybrid protein containing invasin, the product of the inv locus, at its amino-terminal end. Analysis of these gene fusions allowed determination of the direction of translation of the inv gene. Previous studies of Y. pseudotuberculosis invasion have shown that entry into animal cells is temperature regulated. It is shown here that control of expression of the inv gene is also temperature regulated. phoA gene fusions to inv, when present in Y. pseudotuberculosis, were expressed at lower levels when bacteria were grown at 37 degrees C rather than at 28 degrees C. Similar fusions, in contrast, were regulated in a temperature-independent fashion in Escherichia coli, as was the wild-type inv gene. This implies that Y. pseudotuberculosis has chromosomally encoded trans-acting functions that normally thermoregulate expression of inv.
Principles and application of biosensors in microbiology.
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ABC of spinal cord injury. Early management and complications--II.
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ABC of spinal cord injury. Early management and complications--I.
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