The purpose of this study was to evaluate whether a short-form computerized adaptive testing (CAT) version of the Philadelphia Naming Test (PNT) provides error profiles and model-based estimates of ...semantic and phonological processing that agree with the full test.
Twenty-four persons with aphasia took the PNT-CAT and the full version of the PNT (hereinafter referred to as the "full PNT") at least 2 weeks apart. The PNT-CAT proceeded in two stages: (a) the PNT-CAT30, in which 30 items were selected to match the evolving ability estimate with the goal of producing a 50% error rate, and (b) the PNT-CAT60, in which an additional 30 items were selected to produce a 75% error rate. Agreement was evaluated in terms of the root-mean-square deviation of the response-type proportions and, for individual response types, in terms of agreement coefficients and bias. We also evaluated agreement and bias for estimates of semantic and phonological processing derived from the semantic-phonological interactive two-step model (SP model) of word production.
The results suggested that agreement was poorest for semantic, formal, mixed, and unrelated errors, all of which were underestimated by the short forms. Better agreement was observed for correct and nonword responses. SP model weights estimated by the short forms demonstrated no substantial bias but generally inadequate agreement with the full PNT, which itself showed acceptable test-retest reliability for SP model weights and all response types except for formal errors.
Results suggest that the PNT-CAT30 and the PNT-CAT60 are generally inadequate for generating naming error profiles or model-derived estimates of semantic and phonological processing ability. Post hoc analyses suggested that increasing the number of stimuli available in the CAT item bank may improve the utility of adaptive short forms for generating error profiles, but the underlying theory also suggests that there are limitations to this approach based on a unidimensional measurement model.
https://doi.org/10.23641/asha.22320814.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Purpose: This meta-analysis synthesizes published studies using "treatment of underlying forms" (TUF) for sentence-level deficits in people with aphasia (PWA). The study aims were to examine ...group-level evidence for TUF efficacy, to characterize the effects of treatment-related variables (sentence structural family and complexity; treatment dose) in relation to the Complexity Account of Treatment Efficacy (CATE) hypothesis, and to examine the effects of person-level variables (aphasia severity, sentence comprehension impairment, and time postonset of aphasia) on TUF response. Method: Data from 13 single-subject, multiple-baseline TUF studies, including 46 PWA, were analyzed. Bayesian generalized linear mixed-effects interrupted time series models were used to assess the effect of treatment-related variables on probe accuracy during baseline and treatment. The moderating influence of person-level variables on TUF response was also investigated. Results: The results provide group-level evidence for TUF efficacy demonstrating increased probe accuracy during treatment compared with baseline phases. Greater amounts of TUF were associated with larger increases in accuracy, with greater gains for treated than untreated sentences. The findings revealed generalization effects for sentences that were of the same family but less complex than treated sentences. Aphasia severity may moderate TUF response, with people with milder aphasia demonstrating greater gains compared with people with more severe aphasia. Sentence comprehension performance did not moderate TUF response. Greater time postonset of aphasia was associated with smaller improvements for treated sentences but not for untreated sentences. Conclusions: Our results provide generalizable group-level evidence of TUF efficacy. Treatment and generalization responses were consistent with the CATE hypothesis. Model results also identified person-level moderators of TUF (aphasia severity, time postonset of aphasia) and preliminary estimates of the effects of varying amounts of TUF for treated and untreated sentences. Taken together, these findings add to the TUF evidence and may guide future TUF treatment-candidate selection.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Evidence regarding the effect of conversationally based communication group treatment on discourse production in aphasia is limited. Given the rich, complex communication experiences provided in ...these groups, it seemed plausible that participation in them could result in improvement of simpler aspects of discourse production.
To examine the effects of group communication treatment on the informativeness and efficiency of structured and conversational discourse tasks in adults with chronic aphasia.
The data for this study were discourses elicited prospectively from 23 adults with chronic aphasia by Elman & Bernstein-Ellis (1999a) as part of their randomised controlled trial, but never previously transcribed or analyzed. We evaluated changes in discourse informativeness and efficiency at treatment exit and follow-up with Bayesian generalised linear mixed-effects models. Individual effect sizes at exit and follow-up were estimated and a region-of-practical-equivalence approach was used to evaluate whether the posterior distributions at each timepoint for each participant were clinically meaningful.
Results at the group level revealed that structured discourses became more informative and efficient after treatment, and that this improvement was at least maintained at follow-up. Informativeness of conversational discourse did not change from treatment entry to exit, but there was modest evidence of improvement at follow-up. There was no evidence of change to the efficiency of conversational discourse at either timepoint. There was wide variability in individual response to the treatment.
Participation in conversation-based communication group treatment was associated with more informative and efficient structured discourse production and modestly improved informativeness in conversational discourse. Examining individual responses to treatment provided additional insight about the group-level outcomes and provided some clues about factors that might have influenced performance for some of the participants.
Evidence suggests that communication-based aphasia group treatment may increase formal assessment scores and improve features of discourse production. The real-life interactions which occur during ...group treatment may increase use of grammatically complete and relevant utterances.
To examine the effects of communication-based group treatment on production of complete utterances during structured and conversational discourse in adults with chronic aphasia.
We analyzed structured and conversational discourse samples from 23 adults with chronic aphasia originally collected by Elman and Bernstein-Ellis (1999a). Bayesian generalized linear mixed-effects models were used to evaluate changes in use of complete utterances and its two components, syntactic completeness and relevance, at treatment exit and 4-6 weeks post-treatment.
Results are presented with reference to the region of practical equivalence (ROPE, i.e., the range of effect sizes small enough to ignore) and in terms of the probability, derived from Bayesian model posterior distributions, that the effect in question exceeded, fell within, or fell below the ROPE. At the group level, syntactic completeness improved in structured discourse, but syntactic completeness, relevance, and complete utterances did not change during conversational discourse. Individual response to treatment varied and participants with mild aphasia and without concomitant apraxia of speech were more likely to demonstrate post-treatment change in complete utterances.
Use of syntactically complete utterances during structured discourse increased at treatment exit and follow-up. Participants, especially those with severe aphasia and apraxia of speech, may have changed in ways not revealed by the complete utterance measure.
Small-
studies are the dominant study design supporting evidence-based interventions in communication science and disorders, including treatments for aphasia and related disorders. However, there is ...little guidance for conducting reproducible analyses or selecting appropriate effect sizes in small-
studies, which has implications for scientific review, rigor, and replication. This tutorial aims to (a) demonstrate how to conduct reproducible analyses using effect sizes common to research in aphasia and related disorders and (b) provide a conceptual discussion to improve the reader's understanding of these effect sizes.
We provide a tutorial on reproducible analyses of small-
designs in the statistical programming language R using published data from Wambaugh et al. (2017). In addition, we discuss the strengths, weaknesses, reporting requirements, and impact of experimental design decisions on effect sizes common to this body of research.
Reproducible code demonstrates implementation and comparison of within-case standardized mean difference, proportion of maximal gain, tau-U, and frequentist and Bayesian mixed-effects models. Data, code, and an interactive web application are available as a resource for researchers, clinicians, and students.
Pursuing reproducible research is key to promoting transparency in small-
treatment research. Researchers and clinicians must understand the properties of common effect size measures to make informed decisions in order to select ideal effect size measures and act as informed consumers of small-
studies. Together, a commitment to reproducibility and a keen understanding of effect sizes can improve the scientific rigor and synthesis of the evidence supporting clinical services in aphasiology and in communication sciences and disorders more broadly. Supplemental Material and Open Science Form: https://doi.org/10.23641/asha.21699476.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Purpose: In this study, we investigated the agreement between the 175-item Philadelphia Naming Test (PNT; Roach, Schwartz, Martin, Grewal, & Brecher, 1996) and a 30-item computer adaptive PNT ...(PNT-CAT; Fergadiotis, Kellough, & Hula, 2015; Hula, Kellough, & Fergadiotis, 2015) created using item response theory (IRT) methods. Method: The full PNT and the PNT-CAT were administered to 47 participants with aphasia in counterbalanced order. Latent trait-naming ability estimates for the 2 PNT versions were analyzed in a Bayesian framework, and the agreement between them was evaluated using correlation and measures of constant, variable, and total error. We also evaluated the extent to which individual pairwise differences were credibly greater than 0 and whether the IRT measurement model provided an adequate indication of the precision of individual score estimates. Results; The agreement between the PNT and the PNT-CAT was strong, as indicated by high correlation (r = 0.95, 95% CI 0.92, 0.97), negligible bias, and low variable and total error. The number of statistically robust pairwise score differences did not credibly exceed the Type I error rate, and the precision of individual score estimates was reasonably well predicted by the IRT model. Discussion: The strong agreement between the full PNT and the PNT-CAT suggests that the latter is a suitable measurement of anomia in group studies. The relatively robust estimates of score precision also suggest that the PNT-CAT can be useful for the clinical assessment of anomia in individual cases. Finally, the IRT methods used to construct the PNT-CAT provide a framework for additional development to further reduce measurement error.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Purpose: The purpose of this study was to verify the equivalence of 2 alternate test forms with nonoverlapping content generated by an item response theory (IRT)--based computer-adaptive test (CAT). ...The Philadelphia Naming Test (PNT; Roach, Schwartz, Martin, Grewal, & Brecher, 1996) was utilized as an item bank in a prospective, independent sample of persons with aphasia. Method: Two alternate CAT short forms of the PNT were administered to a sample of 25 persons with aphasia who were at least 6 months postonset and received no treatment for 2 weeks before or during the study. The 1st session included administration of a 30-item PNT-CAT, and the 2nd session, conducted approximately 2 weeks later, included a variable-length PNT-CAT that excluded items administered in the 1st session and terminated when the modeled precision of the ability estimate was equal to or greater than the value obtained in the 1st session. The ability estimates were analyzed in a Bayesian framework. Results: The 2 test versions correlated highly (r = 0.89) and obtained means and standard deviations that were not credibly different from one another. The correlation and error variance between the 2 test versions were well predicted by the IRT measurement model. Discussion: The results suggest that IRT-based CAT alternate forms may be productively used in the assessment of anomia. IRT methods offer advantages for the efficient and sensitive measurement of change over time. Future work should consider the potential impact of differential item functioning due to person factors and intervention-specific effects, as well as expanding the item bank to maximize the clinical utility of the test.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
A unifying feature of eukaryotic nuclear organization is genome segregation into transcriptionally active euchromatin and transcriptionally repressed heterochromatin. In metazoa, lamin proteins ...preserve nuclear integrity and higher order heterochromatin organization at the nuclear periphery, but no non-metazoan lamin orthologues have been identified, despite the likely presence of nucleoskeletal elements in many lineages. This suggests a metazoan-specific origin for lamins, and therefore that distinct protein elements must compose the nucleoskeleton in other lineages. The trypanosomatids are highly divergent organisms and possess well-documented but remarkably distinct mechanisms for control of gene expression, including polycistronic transcription and trans-splicing. NUP-1 is a large protein localizing to the nuclear periphery of Trypanosoma brucei and a candidate nucleoskeletal component. We sought to determine if NUP-1 mediates heterochromatin organization and gene regulation at the nuclear periphery by examining the influence of NUP-1 knockdown on morphology, chromatin positioning, and transcription. We demonstrate that NUP-1 is essential and part of a stable network at the inner face of the trypanosome nuclear envelope, since knockdown cells have abnormally shaped nuclei with compromised structural integrity. NUP-1 knockdown also disrupts organization of nuclear pore complexes and chromosomes. Most significantly, we find that NUP-1 is required to maintain the silenced state of developmentally regulated genes at the nuclear periphery; NUP-1 knockdown results in highly specific mis-regulation of telomere-proximal silenced variant surface glycoprotein (VSG) expression sites and procyclin loci, indicating a disruption to normal chromatin organization essential to life-cycle progression. Further, NUP-1 depletion leads to increased VSG switching and therefore appears to have a role in control of antigenic variation. Thus, analogous to vertebrate lamins, NUP-1 is a major component of the nucleoskeleton with key roles in organization of the nuclear periphery, heterochromatin, and epigenetic control of developmentally regulated loci.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Steady-state level of nucleolar P120 protein and P120 mRNA was compared to the doubling time and S-phase fraction in human breast cancer cell lines growing exponentially and in similar cells treated ...with a single dose of P120 antisense oligodeoxynucleotides. The study included six breast cancer cell lines and one nontransformed breast cell line with doubling times from 1.1 to 5.5 days and with S-phase fractions from 35 to 9%. P120 expression level was determined by densitometric computerized evaluation of protein and mRNA blots and with a quantitative 32P-reverse transcriptase-polymerase chain reaction method developed for small-scale samples. In the slowest growing normal cell line, P120 expression level was only about 10% of the level found in the most rapidly growing cancer cell line. The amount of P120 mRNA was highly correlated with the amount of P120 protein (P = 0.0001), indicating that P120 accumulation is regulated in these cells primarily at a transcriptional level. There was also a significant positive correlation between the level of P120 protein/mRNA and doubling time of cell lines (P = 0.0008) or percentage of S-phase cells (P = 0.210). P120 antisense oligomer treatment decreased the growth rate of cells in a dose-dependent manner, and the inhibition reached 70% at 100 microM concentration. Both P120 mRNA and P120 protein levels were also decreased by approximately 70% in cells treated with 100 microM P120 antisense oligomer. Slowly growing cells exhibited 50% inhibition by treatment at a proportionally lower concentration of P120 antisense oligomer than fast growing cells. This study shows that the expression of P120, measured either at the protein or the mRNA level, correlates with proliferation rate, identifying P120 as a cell proliferation marker.
An optimization of the performance of CsI(Na) scintillators coupled to a photomultiplier and irradiated by γ rays is presented. Earlier studies showed that scintillators exhibiting two or more light ...pulse components in the deexcitation process (e.g. CsI(Tl), Nal(Tl) in reduced temperatures) perform better when longer integration time is set in the amplifier. Such properties like energy resolution and non-proportional response improve while lengthening shaping time in the amplifier. At 12 μs shaping time constant the measured energy resolution for a special grade Ø1"× 1" CsI(Na) sample was as good as 5.8±0.1%. Light pulse shape measurements showed that CsI(Na) scintillators irradiated by spl gamma/ rays deexcite mostly in the microsecond range and the light pulse consists of three components: ˜470 ns (fast), ˜1.8 μs (slow) and ˜8 μs (tail) with the relative intensities about 41%, 28% and 31%, respectively. From the point of view of a potential use of CsI(Na) in homeland security applications the crystal was compared to commonly used Nal(Tl) with taking into account such parameters as: energy resolution, non-proportionality, photopeak efficiency and others.
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