The latent structure and predictors of mood in people with aphasia due to left hemisphere stroke

Most studies of post-stroke mood exclude people with aphasia. Two hundred individuals with aphasia due to left hemisphere stroke of varying acuity, completed a visual analog of mood scale. Factor analysis confirmed a two factor model best represents the relationships among scales, consisting of “anxiety/depression” and “vitality” factors. Unexpectedly, mood factors were not associated with stroke acuity, pre-stroke psychiatric history, or aphasia severity. Self-perceived quality of communication life was associated with “vitality”. We conclude it is important to survey the person with aphasia regarding subjective experiences, and that mood state can be measured in the majority of people with aphasia

Low-cost interference lithography

The authors report demonstration of a low-cost ( ∼ 1000 USD) interference lithography system based on a Lloyd’s mirror interferometer that is capable of ∼ 300 nm pitch patterning. The components include only a 405 nm GaN diode-laser module, a machinist’s block, a chrome-coated silicon mirror, substrate, and double-sided carbon scanning electron microscopy (SEM) tape. The laser and the machinist’s block were assembled in a linear configuration, and to complete the system, the mirror and substrate were taped to perpendicular surfaces of the machinist’s block. Approximately 50 silicon substrates were prepared, exposed, and developed, after which some were inspected in a SEM. The associated laser spectrum was also measured, enabling calculation of the laser’s fringe visibility as it varied along the substrate surface. To compare the exposed resist pattern to the fringe visibility, the authors measured the first order diffraction efficiency as a function of position along the grating surface. Their measurements indicated that artifacts seen in both the optical spectrum and resulting grating patterns arose from the laser diode source, thus improving the source characteristics will be the topic of future work.Singapore-MIT Alliance for Research and Technolog

Resolution limits and process latitude of comformable contact nano-lithography

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 78-80).Conformable Contact Lithography enables researchers to attain high-resolution lithographic patterning at manageable cost. This thesis characterizes the minimum resolvable feature size and process latitude of Conformable Contact Lithography. Beginning with a review of current lithographic patterning techniques, choice of Conformable Contract Lithography as an exposure technique is discussed. A design for a trilayer stack that optimizes optical properties is established using experimental and simulated reflectance data to choose appropriate stack film thicknesses. The simulated process latitude is constructed using electromagnetic simulations of grating patterns. Image analysis of experimentally-exposed diffraction grating patterns is described and used to characterize the effect of exposure dose on printed linewidth. The resulting simulated and experimental process latitudes for printed gratings are presented for masks utilizing protruding chrome lines and embedded chrome lines. Experimental and simulated reflectance for single-layer and bilayer film stacks are compared to yield an optimized trilayer stack design of 225nm of anti-reflection-coating chemically separated from the resist by 70nm of evaporated silicon oxide. This design results in less than 1.5% back-reflection from the oxide into the resist for 10% film thickness variation. Finite-difference time-domain simulations are optimized by comparing higher variable-resolution, more realistic simulations to more efficient, lower variable-resolution simulations. Building on the trilayer stack and optimal simulation specification, simulated exposures of diffraction gratings are analyzed assuming a clipping model of development. Exposures of dense grating patterns with two geometries are performed on trilayer-stack-coated silicon wafers for a range of doses.(cont.) Transferred grating patterns are analyzed to establish the effect of exposure dose on printed linewidth. A 5% experimental process latitude is achieved at a printed linewidth tolerance of ±15% for the embedded chrome mask exposures and of 25% for the protruding chrome mask exposures. Within the resist, contrast is higher at smaller gratings using the embedded mask.by Corey Patrick Fucetola.M.Eng

Family ratings of communication largely reflect expressive language and conversation-level ability in people with aphasia

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Constraint Treatment for Chronic Aphasia: Do Treatment Gains Generalize to Story Retelling?

The current investigation included 8 participants with aphasia of greater than 3 years duration in Constraint-Induced Language Therapy (CILT). We sought to determine if CILT treatment gains generalized to Narrative Story Card (Helm-Estabrooks & Nicholas, 2003) retelling. We examined two outcome measures, number words produced and content information units, to determine whether quantity of language, quality of language, or both increased with CILT. Although CILT was beneficial to people with chronic aphasia, gains made in treatment generalized only modestly to Narrative Story Card retelling for most participants. Performance across individuals was quite variable and was not well-characterized by group performance

Assessing the treatment effects in apraxia of speech: introduction and evaluation of the Modified Diadochokinesis Test

Background: The number of reliable and valid instruments to measure the effects of therapy in apraxia of speech (AoS) is limited. Aims: To evaluate the newly developed Modified Diadochokinesis Test (MDT), which is a task to assess the effects of rate and rhythm therapies for AoS in a multiple baseline across behaviours design. Methods: The consistency, accuracy and fluency of speech of 24 adults with AoS and 12 unaffected speakers matched for age, gender and educational level were assessed using the MDT. The reliability and validity of the instrument were considered and outcomes compared with those obtained with existing tests. Results: The results revealed that MDT had a strong internal consistency. Scores were influenced by syllable structure complexity, while distinctive features of articulation had no measurable effect. The testretest and intra- and inter-rater reliabilities were shown to be adequate, and the discriminant validity was good. For convergent validity different outcomes were found: apart from one correlation, the scores on tests assessing functional communication and AoS correlated significantly with the MDT outcome measures. The spontaneous speech phonology measure of the Aachen Aphasia Test (AAT) correlated significantly with the MDT outcome measures, but no correlations were found for the repetition subtest and the spontaneous speech articulation/prosody measure of the AAT. Conclusions & Implications: The study shows that the MDT has adequate psychometric properties, implying that it can be used to measure changes in speech motor control during treatment for apraxia of speech. The results demonstrate the validity and utility of the instrument as a supplement to speech tasks in assessing speech improvement aimed at the level of planning and programming of speech

Prediction of discharge walking ability from initial assessment in a stroke inpatient rehabilitation facility population

Objectives: To (1) determine which clinical assessments at admission to an inpatient rehabilitation facility (IRF) most simply predict discharge walking ability, and (2) identify a clinical decision rule to differentiate household versus community ambulators at discharge from an IRF. Design: Retrospective cohort study. Setting: IRF. Participants: Two samples of participants (n=110 and 159) admitted with stroke. Interventions: A multiple regression determined which variables obtained at admission (age, time from stroke to assessment, Motricity Index, somatosensation, Modified Ashworth Scale, FIM, Berg Balance Scale, 10-m walk speed) could most simply predict discharge walking ability (10-m walk speed). A logistic regression determined the likelihood of a participant achieving household (= 0.4-0.8m/s; >0.8m/s) ambulation at the time of discharge. Validity of the results was evaluated on a second sample of participants. Main Outcome Measure: Discharge 10-m walk speed. Results: Admission Berg Balance Scale and FIM walk item scores explained most of the variance in discharge walk speed. The odds ratio of achieving only household ambulation at discharge was 20 (95% confidence interval [CI], 6-63) for sample I and 32 (95% CI, 10-96) for sample 2 when the combination of having a Berg Balance Scale score of <= 20 and a FIM walk item score of 1 or 2 was present. Conclusions: A Berg Balance Scale score of <= 20 and a FIM walk item score of 1 or 2 at admission indicates that a person with stroke is highly likely to only achieve household ambulation speeds at discharge from an IRF

The brain recovery core: Building a system of organized stroke rehabilitation and outcomes assessment across the continuum of care

none10siThis Special Interest article describes a multidisciplinary, interinstitutional effort to build an organized system of stroke rehabilitation and outcomes measurement across the continuum of care. This system is focused on a cohort of patients who are admitted with the diagnosis of stroke to our acute facility, are discharged to inpatient and/or outpatient rehabilitation at our free-standing facility, and are then discharged to the community. This article first briefly explains the justification, goals, and purpose of the Brain Recovery Core system. The next sections describe its development and implementation, with details on the aspects related to physical therapy. The article concludes with an assessment of how the Brain Recovery Core system has changed and improved delivery of rehabilitation services. It is hoped that the contents of this article will be useful in initiating discussions and potentially facilitating similar efforts among other centers.mixedLang, Catherine E.; Bland, Marghuretta D.; Connor, Lisa Tabor; Fucetola, Robert; Whitson, Michelle; Edmiaston, Jeff; Karr, Clayton; Sturmoski, Audra; Baty, Jack; Corbetta, MaurizioLang, Catherine E.; Bland, Marghuretta D.; Connor, Lisa Tabor; Fucetola, Robert; Whitson, Michelle; Edmiaston, Jeff; Karr, Clayton; Sturmoski, Audra; Baty, Jack; Corbetta, Maurizi