819 research outputs found
The Interchangeability of CVLT-II and WMS-IV Verbal Paired Associates Scores: A Slightly Different Story
We investigated the similarity of the Wechsler Memory Scale-Fourth Edition (WMS-IV) Auditory Memory Index (AMI) scores when California Verbal Learning Test-Second Edition (CVLT-II) scores are substituted for WMS-IV Verbal Paired Associates (VPA) subtest scores. College students (n = 103) were administered select WMS-IV subtests and the CVLT-II in a randomized order. Immediate and delayed VPA scaled scores were significantly greater than VPA substitute scaled scores derived from CVLT-II performance. At the Index level, AMI scores were significantly lower when CVLT-II scores were used in place of VPA scores. It is important that clinicians recognize the accepted substitution of CVLT-II scores can result in WMS-IV scores that are inconsistent with those derived from standard administration. Psychometric issues that plausibly contribute to these differences and clinical implications are discussed
Comparison of Wechsler Memory ScaleāFourth Edition (WMSāIV) and Third Edition (WMSāIII) dimensional structures: Improved ability to evaluate auditory and visual constructs
Dimensional structures underlying the Wechsler Memory ScaleāFourth Edition (WMSāIV) and Wechsler Memory ScaleāThird Edition (WMSāIII) were compared to determine whether the revised measure has a more coherent and clinically relevant factor structure. Principal component analyses were conducted in normative samples reported in the respective technical manuals. Empirically supported procedures guided retention of dimensions. An invariant two-dimensional WMSāIV structure reflecting constructs of auditory learning/memory and visual attention/memory (C1 = .97; C2 = .96) is more theoretically coherent than the replicable, heterogeneous WMSāIII dimension (C1 = .97). This research suggests that the WMSāIV may have greater utility in identifying lateralized memory dysfunction
The Role of Neurocognitive Tests in the Assessment of Adult Attention-Deficit/Hyperactivity Disorder
Despite widespread recognition that attention-deficit/hyperactivity disorder (ADHD) is a lifelong neurodevelopmental disorder, optimal methods of diagnosis among adults remain elusive. Substantial overlap between ADHD symptoms and cognitive symptoms of other mental health conditions, such as depression and anxiety, and concerns about validity in symptom reporting have made the use of neuropsychological tests in ADHD diagnostic assessment appealing. However, past work exploring the potential diagnostic utility of neuropsychological tests among adults has often relied on a relatively small subset of tests, has failed to include symptom and performance validity measures, and often does not include comparison groups of participants with commonly comorbid disorders, such as depression. The current study examined the utility of an extensive neuropsychological measure battery for diagnosing ADHD among adults. Two hundred forty-six participants (109 ADHD, 52 depressed, 85 nondisordered controls) completed a multistage screening and assessment process, which included a clinical interview, self, and informant report on behavior rating scales, performance and symptom validity measures, and an extensive neuropsychological testing battery. Results indicated that measures of working memory, sustained attention, response speed, and variability best discriminated ADHD and non-ADHD participants. While single test measures provided performed poorly in identifying ADHD participants, analyses revealed that a combined approach using self and informant symptom ratings, positive family history of ADHD, and a reaction time (RT) variability measure correctly classified 87% of cases. Findings suggest that neuropsychological test measures used in conjunction with other clinical assessments may enhance prediction of adult ADHD diagnoses
Flexible adaptation of iterative learning control with applications to synthetic bone graft manufacturing
Additive manufacturing processes are powerful tools; they are capable of fabricating structures without expensive structure specific tooling -- therefore structure designs can efficiently change from run-to-run -- and they can integrate multiple distinct materials into a single structure. This work investigates one such additive manufacturing process, micro-Robotic Deposition (RD), and its utility in fabricating advanced architecture synthetic bone grafts. These bone grafts, also known as synthetic bone scaffolds, are highly porous three-dimensional structures that provide a matrix to support the natural process of bone remodeling. Ideally, the synthetic scaffold will stimulate complete bone healing in a skeletal defect site and also resorb with time so that only natural tissue remains.
The objective of this research is to develop methods to integrate different regions with different porous microstructures into a single scaffold; there is evidence that scaffolds with designed regions of specific microstructures can be used to elicit a strong and directed bone ingrowth response that improves bone ingrowth rate and quality. The key contribution of this work is the development of a control algorithm that precisely places different build materials in specified locations, thereby the fabrication of advanced architecture scaffolds is feasible. Under previous control methods, designs were relegated to be composed of a single material. The control algorithm developed in this work is an adaptation of Iterative Learning Control (ILC), a control method that is typically best suited for mass manufacturing applications. This adaptation reorients the ILC framework such that it is more amenable to additive manufacturing systems, such as RD. Control efficacy is demonstrated by the fabrication of advanced architecture scaffolds. Scaffolds with contoured forms, multiple domains with distinct porous microstructures, and hollow cavities are feasible when the developed controller is used in conjunction with a novel manufacturing workflow in which scaffolds are filled within patterned molds that support overhanging features. An additional application demonstrates controller performance on the robot positioning problem; this work has implications for additive manufacturing in general
The Cytoskeletal Mechanisms of Cell-Cell Junction formation in Endothelial Cells
Intercellular adhesions are essential for compartmentalization and integrity of tissues in an organism, cell-cell communication, and morphogenesis. The actin cytoskeleton and associated proteins play a vital role in establishing and maintaining cell-cell adhesion. However, the procedure by which cells establish adherens junctions remains largely unclear.
We investigated the dynamics of cell-cell junction formation and the corresponding architecture of the underlying cytoskeleton in cultured human umbilical vein endothelial cells (HUVECs). We show that the initial interaction between cells is mediated by protruding lamellipodia. Upon their retraction, cells maintain contact through thin bridges formed by filopodia-like protrusions connected by VE-cadherin-rich junctions.
Bridges share multiple features with conventional filopodia, such as an internal actin bundle associated with fascin along the length and VASP at the tip. Strikingly, unlike conventional filopodia, transformation of actin organization from the lamellipodial network to filopodial bundle during bridge formation occurs in a proximal-to-distal direction and is accompanied by recruitment of fascin in the same direction. Subsequently, bridge bundles recruit nonmuscle myosin II and mature into stress fibers. Myosin II activity was important for bridge formation and accumulation of VE-cadherin in nascent adherens junctions. Our data reveal a mechanism of cell-cell junction formation in endothelial cells utilizing lamellipodia as the initial protrusive contact, subsequently transforming into filopodia-like bridges connected through adherens junctions. Moreover, a novel lamellipodia-to-filopodia transition is employed in this context
The Impact of Failing to Identify Suspect Effort in Patients Undergoing Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Assessment
This retrospective study examines how many adult patients would plausibly receive a diagnosis of attention-deficit/hyperactivity disorder (ADHD) if performance and symptom validity measures were not administered during neuropsychological evaluations. Five hundred fifty-four patients were extracted from an archival clinical dataset. A total of 102 were diagnosed with ADHD based on cognitive testing, behavior rating scales, effort testing, and clinical interview; 115 were identified as putting forth suspect effort in accordance with the Slick, Sherman, and Iverson (1999) criteria. From a clinical decision-making perspective, suspect effort and ADHD groups were nearly indistinguishable on ADHD behavior, executive function, and functional impairment rating scales, as well as on cognitive testing and key clinical interview questions. These results suggest that a significant percentage of those making a suspect effort will be diagnosed with ADHD using the most commonly employed assessment methods: an interview alone (71%); an interview and ADHD behavior rating scales combined (65%); and an interview, behavior rating scales, and most continuous performance tests combined (57%). This research makes clear that it is essential to evaluate task engagement and possible symptom amplification during clinical evaluations
Antibodies to actin in autoimmune haemolytic anaemia
BACKGROUND: In autoimmune haemolytic anaemia (AIHA) autoreactive antibodies directed against red blood cells are upregulated leading to erythrocyte cell death. M. suis infections in pigs (IAP) induce AIHA of both the warm and the cold type. Aim of this study was to identify target autoantigens of warm autoreactive IgG antibodies. For this, sera from experimentally M. suis infected pigs were screened for autoreactivity. RESULTS: In sera of 95 % of all tested animals actin-reactive antibodies were found. The reactivity was shown to be species specific, i.e. reactivity with porcine actin was significantly higher than with rabbit-actin. Sera of animals previously immunised with the adhesion protein MSG1 of M. suis showed reactivity with actin prior to infection with M. suis indicating molecular mimicry to be involved in specific autoreactive mechanism. A potentially cross reactive epitope could be detected. CONCLUSIONS: This is the first report of autoreactive anti-actin antibodies involved in pathogenesis of autoimmune haemolytic anaemia
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